Answer:
Climate
Explanation:
Tungsten (W) and chlorine (Cl) form a series of compounds with the following compositions:_______.
Mass % W Mass % Cl
72.17 27.83
56.45 43.55
50.91 49.09
46.36 53.64
If a molecule of each compound contains only one tungsten atom, what are the formulas for the four compounds?
Answer:
WCl₂, WCl₄, WCl₅, WCl₆
Explanation:
Molar Mass of Tungsten = 184 g/mol
Mass of Chlorine = 35.5 g/mol
In the first compound;
Percentage of tungsten = 72.17 %
Upon solving;
72.17 % = 184
100 % = Total mass
Total mass of compound = 254.95g
Mass of chlorine = 254.95 - 184 = 70.95 (Dividing by 35.35; This is approximately 2 Chlorine atoms.
The Formular is WCl₂
In the second compound;
Percentage of tungsten = 56.45 %
Upon solving;
56.45 % = 184
100 % = Total mass
Total mass of compound = 325.95 g
Mass of chlorine = 325.95 - 184 = 141.95g (Dividing by 35.35; This is approximately 4 Chlorine atoms.
The Formular is WCl₄
In the third compound;
Percentage of tungsten = 50.91 %
Upon solving;
50.91 % = 184
100 % = Total mass
Total mass of compound = 361.42 g
Mass of chlorine = 361.42 - 184 = 177.42 (Dividing by 35.35; This is approximately 5 Chlorine atoms.
The Formular is WCl₅
In the fourth compound;
Percentage of tungsten = 46.39 %
Upon solving;
46.39 % = 184
100 % = Total mass
Total mass of compound = 396.64 g
Mass of chlorine = 396.64 - 184 = 212.64 (Dividing by 35.35; This is approximately 6 Chlorine atoms.
The Formular is WCl₆
Three colorless solutions in test tubes, with no labels, are in a test tube rack on the laboratory bench. Lying beside the tests tubes are three labels : 0.10 M Na2CO3, 0.10 M HCL, and 0.10 M KOH. You are to place the labels on the test tubes using only the three solutions present. Here are your tests:
A few drops of the solutions from test tube 1 added to a similar volume of the solution in test tube 2 produces no visible reaction but the solution becomes warm.
A few drops of the solution from test tube 1 added to a similar volume of the solution in test tube 3 produces carbon dioxide gas.
Identify the labels for test tubes 1, 2, and 3
Answer:
Test tube 1 0.10 M HCL
Test tube 2 0.10 M KOH
Test tube 3 0.10 M Na2CO3
Explanation:
From the question we are told that
A few drops of the solutions from test tube 1 added to a similar volume of the solution in test tube 2 produces no visible reaction but the solution becomes warm
Generally this warmth is as a result of a reaction between an acid and a base and the acid is 0.10 M HCL and the base is 0.10 M KOH , the heat generated is know as the heat of neutralization,
The reaction is
[tex]HCl_{(aq)} + KOH_{(aq)} \rightarrow KCl_{(aq)} + H_2O_{(l)} + \Delta H[/tex]
We are also told from the reaction that
A few drops of the solution from test tube 1 added to a similar volume of the solution in test tube 3 produces carbon dioxide gas.
Generally carbon dioxide gas is produced is as a result of a reaction between the acid HCl and Na2CO3.
The reaction is
[tex]2HCl -{(aq)} + Na_2 CO_3_{(aq)} \rightarrow 2 NaCl _{(aq)} + CO_2_{(g)} + H_2O_{(l)}[/tex]
Hence from this explanation above we see that the solution in test tube 1 is 0.10 M HCL while solution in test tube 2 is 0.10 M KOH and then solution in test tube three is 0.10 M Na2CO3
For the combustion of methane presented in Example 5.4, the chemical reaction is CH4 +2O2 →CO2 +2H2O Suppose that methane flows into a burner at 30 gmol/s, while oxygen flows into the same burner at 75 gmol/s. If all the meth- ane is burned and a single output stream leaves the burner, what is the mole fraction of CO2 in that output stream? Hint 1: Does the fact that all the methane is burned mean that all the oxygen is burned also? Hint 2: Find the molar flow rate of each component gas in the outlet gas ("flue gas").
Answer:
[tex]x_{CO_2}^{out} =0.25[/tex]
Explanation:
Hello.
In this case, for the reactive scheme, it is very convenient to write each species' mole balance as shown below:
[tex]CH_4:f_{CH_4}^{out}=f_{CH_4}^{in}-\epsilon \\\\O_2:f_{O_2}^{out}=f_{O_2}^{in}-2\epsilon\\\\CO_2:f_{CO_2}^{out}=\epsilon\\\\H_2O:f_{H_2O}^{out}=2\epsilon[/tex]
Whereas [tex]\epsilon[/tex] accounts for the reaction extent. However, as all the methane is consumed, from the methane balance:
[tex]0=f_{CH_4}^{in}-\epsilon \\\\\epsilon=30gmol/s[/tex]
Thus, we can compute the rest of the outlet mole flows since not all the oxygen is consumed as it is in excess:
[tex]f_{O_2}^{out}=f_{O_2}^{in}-2\epsilon=75gmol/s-2*30gmol/s=15gmol/s\\\\f_{CO_2}^{out}=15gmol/s\\\\f_{H_2O}^{out}=2*15gmol/s=30gmol/s[/tex]
It means that the mole fraction of carbon dioxide in that output is:
[tex]x_{CO_2}^{out}=\frac{15}{15+15+30} =0.25[/tex]
Best regards.
The ion with the smallest diameter is ________. The ion with the smallest diameter is ________. Be2 Sr2 Ca2 Ba2 Mg2
Answer:
Be2^+
Explanation:
Ionic diameter increases down the group. This implies that Be2^+ will have the smallest diameter.
This extremely small diameter makes Be2^+ to differ considerably from other ions of group 2 elements.
For instance, the compounds of beryllium are mostly covalent in nature.
How many carbon atoms are in vitamin c?
Answer:
molecules can be much bigger. one molecule of vitamin c is made up of 20 atoms (6 carbons, 8 hydrogens, and 6 oxygens
A piece of metal has a mass of 0.650 kilograms, has a width of 0.136 meters, and has a length of 0.0451 meters.Part A: If the metal’s volume is 291 cm3, what is the height of the metal in centimeters? (The width & length values given above are in a different unit!)
Part B: What is the density of this piece of metal?
Answer:
height = 4.74 cm
density = 2.23 g/ cm³
Explanation:
Mass of metal = 0.650 kg (650 g)
Width = 0.136 m
Length = 0.0451 m
Volume of metal = 291 cm³
Height in cm = ?
density of metal =?
Solution:
Width = 0.136 m (0.136 m×100 cm/1m = 13.6 cm)
Length = 0.0451 m (0.0451 m×100 cm/1m = 4.51 cm)
First of all we will calculate the height:
Volume = height× width× length
291 cm³ = h × 13.6 cm × 4.51 cm
291 cm³ = h × 61.34 cm²
h = 291 cm³ / 61.34 cm²
h = 4.74 cm
Density:
d = m/v
d = 650 g/291 cm³
d = 2.23 g/ cm³
3. How can the force of gravity affect weight?
On the graph, which shows the potential energy curve of two N atoms, carefully sketch a curve that corresponds to the potential energy of two O atoms versus the distance between their nuclei.
Answer:
Explanation:
We are to carefully sketch a curve that relates to the potential energy of two O atoms versus the distance between their nuclei.
From the diagram, O2 have higher potential energy than the N2 molecule. Because on the periodic table, the atomic size increases from left to right on across the period, thus O2 posses a larger atomic size than N2 atom.
Therefore, the bond length formation between the two O atoms will be larger compared to that of the two N atoms.
What is the maximum amount of water (in grams) that can be removed from 15ml of toluene by the addition?
Complete Question
Magnesium sulfate forms a hydrate with the formula [tex]MgSO_4. 7H_20[/tex]. What is the maximum amount of water (in grams) that can be removed from 15 ml of toluene by the addition of 200 mg of anhydrous magnesium sulfate? The molar mass of [tex]MgSO_4[/tex] is 120.4 g/mol; H20 = 18 g/mol.
Answer:
The value is [tex]z = 0.2093 \ g[/tex] of [tex]H_2O[/tex]
Explanation:
From the question we are told that
The volume of toluene is [tex]V = 15 mL[/tex]
The mass of anhydrous magnesium sulfate is [tex]m = 200m g = 200 *10^{-3} \ g[/tex]
The formula of the hydrate is [tex]MgSO_4. 7H_20[/tex]
The molar mass of [tex]MgSO_4[/tex] is [tex]z =120.4 \ g/mol[/tex]
From the formula given we see that
1 mole of [tex]Mg SO_4[/tex] wil remove 7 moles of [tex]H_2O[/tex] to for the given formula
Hence
120.4 g (1 mole) will remove 7 moles (7 * 18 g = 126 g ) of [tex]H_2O[/tex] to for the given formula
Therefore 1 g of [tex]Mg SO_4[/tex] x g of [tex]H_2O[/tex]
So
[tex]x = \frac{x]126 * 1}{ 120.4 }[/tex]
=> [tex]x = 1.0465 \ g [/tex]
From our calculation we obtained that
1 g of [tex]Mg SO_4[/tex] will remove [tex]x = 1.0465 \ g [/tex] of [tex]H_2O[/tex]
Then
[tex]200 *10^{-3} \ g[/tex] of [tex]Mg SO_4[/tex] will remove z g of [tex]x = 1.0465 \ g [/tex] of [tex]H_2O[/tex]
So
[tex]z = 200 *10^{-3} * 1.0465[/tex]
=>[tex]z = 200 *10^{-3} * 1.0465[/tex]
=>[tex]z = 0.2093 \ g[/tex] of [tex]H_2O[/tex]
A bicycle rider is applying a force of 20 N while heading south against a wind blowing from the south with a force of 5 N
Answer:
the bike will go down 5 N
Radioactive americium-241 is used in household smoke detectors and in bone mineral analysis.
Give the number of electrons, protons, and neutrons in an atom of americium-241.
Answer:
Electrons- 95
Protons- 95
Neutrons-146
Explanation:
An atoms is made up of three fundamental particles; electrons, protons and neutrons,
Americium belongs to the f block in the periodic table. It is an actinide element.
An atom of Am-241 contains 95 protons, 95 electrons and 146 neutrons.
What does the term mass mean in science?
A. The measure of the force of gravity on an object.
B. The amount of matter in an object.
C. The Amount of space that matter takes up.
Answer:
B
Explanation:
Mass is defined as the quantity of matter in an object.
A geochemist has determined by measurements that there are moles of tin in a sample of cassiterite. How many moles of oxygen are in the sample
The question is incomplete, the complete question is:
This is the chemical formula for cassiterite (tin ore): SnO2 A geochemist has determined by measurements that there are 13. moles of tin in a sample of cassiterite. How many moles of oxygen are in the sample? Round your answer to 2 significant digits.
Answer:
Explanation:
In SnO2, there are two moles of oxygen for each mole of tin.
Hence, if there are 13 moles of tin, then we should have 13 * 2 moles of oxygen. This gives us 26 moles of oxygen.
Hence there are 26 moles of oxygen.
Why can we use a water-ethanol mixture but not a water-hexane mixture as a recrystallization solvent? because water and hexane are ___________________.
Answer:
immiscible liquids
Explanation:
When two liquids are to be used for the purpose of recrystallization the both liquids must be miscible with each other in all proportions.
This implies that, if two liquids are immiscible, it will be difficult for the mixture to be useful in recrystallization.
Water and hexane are immiscible because water is a polar solvent and hexane is a non polar solvent.
Water is miscible with ethanol because ethanol contains polar -OH groups that interact effectively with water leading to miscibility of ethanol with water in all proportions.
what kind of bonds are there in H2O?
Answer: it is covalent and there are 2 hydrogen molecules and 1 oxygen molecule.
Explanation: it just is
Rahul and Manav each were given a mixture of iron filings and sulphur powder. Rahul heated the mixture strongly and a new substance was formed. Write three points of difference between the two.Required to answer.
Answer:
sure
Explanation:
The substance formed after heating the mixture of that of Rahul is caleed a compound. Whereas, Manav's mixture still remains in its current stae that is a heterogeneous mixture.
The compound formed is in black in color whereas the mixture is a mix of brownish-red and yellow.
The compound is a homogeneous mixture whereas the mixture is a heterogenous mixture because of its uneven distribution.
What is the mass in grams of 2.5 moles of Al?
Answer:
One mole of Al weighs 27g.
2.5 moles of Al weigh 67.5g.
The chemical formula for sumuric acid is H Son. In one molecule of sulfuric acid, there are____
A. two atoms of hellum
B. two atoms of oxygen
C. four atoms of oxygen
D. four atoms of sulfur oxide
Answer:
I want to say option C: four atoms of oxygen. Sorry if I'm wrong
Which element will gain three electrons to form an anion?
A. aluminum
B. chromium
C. iron
D. nitrogen
Answer:
D represents the element nitrogen which will gain three valence electrons forming a 3 ion.
Answer:
answer is
Explanation:
D
The wood in my house is crumbling. *
Problem
Hypothesis
Law
Theory
Answer:
Problem
Explanation:
The given statement is a problem. It states the problem that the house of the speaker has been undergoing with. This problem gives rise to the Hypothesis in which the 'why' question is asked. The reason of the crumbling of the wood is stated in the hypothesis. Any reason placed of the happening of the event is stated to be hypothesis.
Help plz!!!!!!!!!!!!!!!
Answer:
Albert Einstein proposed that a beam of light is not a wave propagating through space, but a collection of discrete wave packets—photons.
Explanation:
So the right answer is the first one.
1.
Light near the middle of the ultraviolet region of the electromagnetic spectrum
has a frequency of 2.73 X 1016 s-1
a.
What is the wavelength of this radiation in meters (m)?
b.
What is the energy associated with this radiation in kcal?
Explanation:
Given that,
The frequency of electromagnetic spectrum is [tex]2.73\times 10^{16}\ Hz[/tex]
(A) Let the wavelength of this radiation is [tex]\lambda[/tex]. We know that,
[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{2.73\times 10^{16}}\\\\\lambda=1.09\times 10^{-8}\ m[/tex]
So, the wavelength of this radiation is [tex]1.09\times 10^{-8}\ m[/tex].
(B) Let E is the energy associated with this radiation. Energy of an electromagnetic radiation is given by :
[tex]E=hf[/tex]
h is Planck's constant
[tex]E=6.63\times 10^{-34}\times 2.73\times 10^{16}\\\\E=1.8\times 10^{-17}\ J[/tex]
1 kcal = 4184 J
It means,
[tex]1.8\times 10^{-17}\ J=\dfrac{1}{4184}\times 1.8\times 10^{-17}\\\\=4.3\times 10^{-21}\ \text{kcal}[/tex]
Hence, this is the required solution.
what is the point of doing an experiment. Help thank you
Answer:
to find out how somethings work
Explanation:
Answer:
Doing experiments is good because when you try these possibilities you can learn about something that you've tried or see why this experiment didn't really work. It also helps you understand that not everything you try will work. that's why we experiment.
Explanation:
Hope this helps:)
How long would it take a bus traveling 52 km/h to travel 130 km
Answer:
2 and a half hours
Explanation:
Time is equal to distance over speed
If you collect 5.74 mL of O 2 at 298 K and 1.00 atm over 60.0 seconds from a reaction solution of 5.08 mL, what is the initial rate of the reaction
Answer:
7.71 × 10⁻⁴ M/s
Explanation:
The initial rate of the reaction can be expressed by using the formula:
[tex]\dfrac{\Delta [O_2]}{\Delta t}[/tex]
where the number of moles of O₂ = [tex]\dfrac{PV}{RT}[/tex]
where;
Pressue P = 1.00 atm
Volume V =5.74mL = (5.74 /1000) L
Rate R = 0.082 L atm/mol.K
Temperature = 298 K
[tex]= \dfrac{1.00 \ atm \times \dfrac{5.74 }{1000}L}{0.082 \ L \ atm/mol.K \times 298 K}[/tex]
= 2.35 × 10⁻⁴ mol
Δ[O₂] = [tex]\dfrac{moles \ produced - initial \ mole}{\dfrac{5.08 }{1000}L }[/tex]
Δ[O₂] = [tex]\dfrac{2.35 \times 10^{-4} M - 0 M}{\dfrac{5.08 }{1000}}[/tex]
Δ[O₂] = 0.04626 M
The initial rate = [tex]\dfrac{\Delta [O_2]}{\Delta t}[/tex]
= [tex]\dfrac{0.04626}{60}[/tex]
= 7.71 × 10⁻⁴ M/s
2. (6 pts) In a reaction, 235 mL of 1.50 M HCl solution reacts completely with an excess amount of
aluminum. If the hydrogen gas is collected over water in a container with a volume of 3.60 L and at a
temperature of 25.0 °C, calculate the pressure in the container. The vapor pressure of water is 23.78
mmHg (Table 6.4, page 232).
2Al(s) + 6HCl(aq) + 3H2(g) + 2AlCl3(aq)
Answer:
[tex]P=1.23atm[/tex]
Explanation:
Hello.
In this case, since the total pressure in the container includes the pressures of both hydrogen and water:
[tex]P=P_{H_2}+P_{H_2O}[/tex]
For the reacting solution of HCl, based on the 6:3 mole ratio with hydrogen in the chemical reaction, we can next compute the yielded moles o hydrogen:
[tex]n_{H_2}=0.235L*1.50\frac{molHCl}{L}*\frac{3molH_2}{6molHCl} =0.176molH_2[/tex]
Then, by using the ideal gas equation we compute the pressure of hydrogen for the collected 3.60 L at 25.0 °C (298.15 K):
[tex]P_{H_2}=\frac{n_{H_2}RT}{V} =\frac{0.176mol*0.082\frac{atm*L}{mol*K}*298.15K}{3.60L}=1.20atm[/tex]
Finally, since the vapor pressure of water in at is 0.03129, the total pressure is then:
[tex]P=1.20atm+0.03129atm\\\\P=1.23atm[/tex]
Best regards!
Gases A and B are confined to a cylinder and piston and react to form product C. As the reaction occurs, the system loses 1189 J of heat to surroundings. The piston moves downward as the gases react to form a solid. As the volume of the gas decreases under the constant pressure of the atmosphere, the surroundings do 311 J of work on the system. What is the change in the internal energy of the system
Answer:
The change in the internal energy of the system -878 J
Explanation:
Given;
energy lost by the system due to heat, Q = -1189 J (negative because energy was lost by the system)
Work done on the system, W = -311 J (negative because work was done on the system)
change in internal energy of the system, Δ U = ?
First law of thermodynamics states that the change in internal energy of a system (ΔU) equals the net heat transfer into the system (Q) minus the net work done by the system (W).
ΔU = Q - W
ΔU = -1189 - (-311)
ΔU = -1189 + 311
ΔU = -878 J
Therefore, the change in the internal energy of the system -878 J
4. What reagent would you predict to be in excess for reacting 7.50 mL of a 0.10M BaCl2 solution with 7.50 mL of 0.10M KIO3 solution
Answer : [tex]BaCl_2[/tex] reagent predict to be in excess.
Explanation : Given,
Concentration of [tex]BaCl_2[/tex] = 0.10 M
Volume of [tex]BaCl_2[/tex] = 7.50 mL = 0.0075 L (1 L = 1000 mL)
Concentration of [tex]KIO_3[/tex] = 0.10 M
Volume of [tex]KIO_3[/tex] = 7.50 mL = 0.0075 L
First we have to calculate the moles of [tex]BaCl_2[/tex] and [tex]KIO_3[/tex].
[tex]\text{Moles of }BaCl_2=\text{Concentration of }BaCl_2\times \text{Volume of }BaCl_2[/tex]
[tex]\text{Moles of }BaCl_2=0.10M\times 0.0075L=0.00075mol[/tex]
and,
[tex]\text{Moles of }KIO_3=\text{Concentration of }KIO_3\times \text{Volume of }KIO_3[/tex]
[tex]\text{Moles of }KIO_3=0.10M\times 0.0075L=0.00075mol[/tex]
Now we have to calculate the excess and limiting reagent.
The balanced equilibrium reaction will be:
[tex]BaCl_2+2KIO_3\rightleftharpoons Ba(IO_3)_2+2KCl [/tex]
From the balanced reaction we conclude that
As, 2 mole of [tex]KIO_3[/tex] react with 1 mole of [tex]BaCl_2[/tex]
So, 0.00075 moles of [tex]KIO_3[/tex] react with [tex]\frac{0.00075}{2}=0.000375[/tex] moles of [tex]BaCl_2[/tex]
From this we conclude that, [tex]BaCl_2[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]KIO_3[/tex] is a limiting reagent and it limits the formation of product.
Hence, [tex]BaCl_2[/tex] reagent predict to be in excess.
An increase in temperature results in A) a decrease in the required activation energy while the reaction rate remains constant. B) an increase in reaction rate due to a decrease in the kinetic energy of the reactants. C) an increase in the rate of reaction because reactant molecules collide with greater energy. D) an increase in both the reaction rate and activation energy due to increased kinetic energy.
Answer:
C) an increase in rate of reaction because reactant molecules collide with greater energy
Explanation:
Temperature is one of the factors that affect the rate of a reaction. The rate of a reaction increases with an increase in temperature and vice versa. When the temperature of a reaction increases, the kinetic energy of the reactant molecules increases causing them to react at a faster rate.
The reactant molecules respond to an increase in temperature by colliding at a faster rate due to an increased kinetic energy between the reactant molecules.
27.8 mL solution of 0.797 M HCHO2 with 0.928 M NaOH. What is the pH for the solution at the equivalence point in the titration?
Answer:
8.69 is the pH at the equivalence point
Explanation:
Formic acid, HCHO₂, reacts with NaOH as follows:
HCHO₂ + NaOH → NaCHO₂ + H₂O.
At the equivalence point you will have in the reaction just NaCHO₂ and H₂O. The concentration of NaCHO₂ will be:
Moles: 0.0278L * 0.797mol/L = 0.02216moles
To reach the equivalence point it is necessary to add:
0.02216mol * (1L / 0.928mol) = 0.0239L
Total volume in the equivalence point:
0.0278L + 0.0239L = 0.0517L
Concentration: 0.02216moles / 0.0517L = 0.429M
The equilibrium of NaCHO₂, CHO₂⁻, in water is:
CHO₂⁻(aq) + H₂O(l) ⇄ OH⁻(aq) + HCHO₂(aq)
Where Kb, 5.56x10⁻¹¹ is defined as:
5.56x10⁻¹¹ = [OH⁻] [HCHO₂] / [CHO₂⁻]
In the equilibrium, it is produced X OH⁻ and HCHO₂, and as concentration of NaCHO₂ is 0.429M:
5.56x10⁻¹¹ = [X] [X] / [0.429M]
2.383x10⁻¹¹ = X²
4.88x10⁻⁶ = X = [OH⁻]
As pOH = -log [OH⁻]
pOH = 5.31
And pH = 14 - pH
pH = 8.69 is the pH at the equivalence point