Answer: The mole fraction of chloroform in this solution is 0.41
Explanation:
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
a) moles of [tex]CHCl_3[/tex]
[tex]\text{Number of moles}=\frac{49g}{119g/mol}=0.41moles[/tex]
b) moles of [tex]CH_3COBr[/tex]
[tex]\text{Number of moles}=\frac{73g}{123g/mol}=0.59moles[/tex]
To calculate the mole fraction, we use the formula:
[tex]\text{Mole fraction of a component}=\frac{\text{Moles of the component}}{\text{total moles}}[/tex]
[tex]\text{Mole fraction of chloroform}=\frac{\text{Moles of chloroform}}{\text{total moles}}=\frac{0.41}{0.41+0.59}=0.41[/tex]
The mole fraction of chloroform in this solution is 0.41
what element is in group 13, period 4
Answer:
Gallium
Explanation:
Answer:
Gallium
Explanation:
g What amounts of 45% pure silver and 50% pure silver should be mixed to obtain 14 grams of 46% pure silver
Answer:
11.2g of the 45% pure silver and 2.8g of the 50% pure silver.
Explanation:
14g of 46% pure silver contains:
14g*46% = 6.44g of silver are required. Thus, we can write:
6.44 = X*50% + Y*45% (1)
Where X is the mass of 50% pure silver and Y the mass of 45% pure silver.
As the mass of the sample must be 14g:
14g = X + Y (2)
Replacing (2) in (1):
6.44 = (14-Y)*50% + Y*45%
6.44 = 7 - 0.5Y + 0.45Y
-0.56 = -0.05Y
Y = 11.2g of the 45% pure silver
And:
14g-11.2g = X
X =
2.8g of the 50% pure silver
The required amount to obtain 14g of 46% pure silver is 2.8g of 50% silver and 11.2g of 45% silver.
To solve this question, we can assume it's a mathematical problem more than a chemistry problem.
let x represent the amount of 45% of pure Ag
let y represent the amount of 50% of pure Ag
But from the question, we only need 14g from both x and y
We can write an equation to represent this
[tex]x+y=14...equation(i)[/tex]
likewise, we can say that
[tex]0.45x+0.50y=14*0.46\\0.45x+0.50y=6.44...equation(ii)[/tex]
Solving both equations simultaneously,
[tex]x+y=14...equation(i)\\0.45x+0.5y=6.44...equation(ii)[/tex]
from equation (i)
[tex]x+y=14\\x=14-y...equation(iii)[/tex]
substitute equation (iii) into equation (ii)
[tex]0.45x+0.5y=6.44\\x=14-y\\0.45(14-y)+0.5y=6.44\\6.3-0.45y+0.5y=6.44\\[/tex]
collect like terms
[tex]-0.45y+0.50y=6.44-6.3\\0.05y=0.14\\y=\frac{0.14}{0.05}\\y=2.8[/tex]
Now we know the value of the 50% Ag which is 2.8g. Let's substitute it's value into equation (i) and solve for x
[tex]x+y=14\\x+2.8=14\\x=14-2.8\\x=11.2g[/tex]
Learn more about definite proportions here
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Write down the possible types of atomic
Orbitals of n=4
Answer:
2
Explanation:
because first shell ( k shell ) needs only 2 electron to complete its octet .
hope it helps
What carpet Burns in a deficiency of O2 a mixture of CO and CO2 forms.Carbon Burns in excess O2 to form only CO2 and CO Burns in excess O2 to form only CO2. Calculate ΔH for C(graphite +1/2O2) →CO(g).
Answer:
Explanation:
From the combustion of carbon, the reactions occurring in limited oxygen conditions are:
[tex]C(graphite) + \dfrac{1}{2}O_{2(g)} \to CO_{(g)}[/tex]
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]
If it occurs in excess, then any leftover CO changes to CO2. i.e.
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex] ---- (1)
[tex]CO_{(g)} + \dfrac{1}{2}O_{(g)} \to CO_{2(g)}[/tex] ----- (2)
From (1), the enthalpy change is:
[tex]\Delta H_{rxn1} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{f C(graphite)}+ \Delta H^0_{fCO_2(g)}[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol -(0+0)[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol[/tex]
From (2), the enthalpy change is:
[tex]\Delta_{rxn2} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{fCO(g)} + \dfrac{1}{2} \Delta H^0_{fO_2(g)})[/tex]
[tex]\Delta_{rxn2} = -393.5 \ kJ/mol -(-110.5 + \dfrac{1}{2}(0))[/tex]
[tex]\Delta_{rxn2} = -283.0 \ kJ/mol[/tex]
Subtracting (2) from (1), we get:
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)} \ \ \ \Delta H_{rxn} = -393.5 \ kJ/mol}[/tex]
[tex]CO_{(g)} + \dfrac{1}{2} O_2(g) \to CO_{2(g)}} \ \ \ \Delta H _{rxn2} = -283.0 \ kJ/mol[/tex]
[tex]C(graphite) + O_{2(g)} \to CO (g) + \dfrac{1}{2}O_{2(g)} \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
[tex]C(graphite) + \dfrac{1}{2} O_{2(g)} \to CO (g) \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
The enthalpy change ΔH of the reaction = -110.5 kJ/mol
All the radioactive elements are found in the last group of the Periodic Table.
True
False
Answer:
False
Explanation:
Is burning physical or chemical change?
Answer:
a chemical change
Explanation:
lighting a match is a chemical change. chemical reactions cause chemical change. in a chemical reaction two or more substances, called the reactants, form different substances called products. hope this helped :)
two reason that show sugar is compound
Answer:
Table sugar, or sucrose, is a compound because it's formed when two or more elements are joined together. Its chemical formula is C12H22O11, and it contains carbon, hydrogen and oxygen. More specifically, each molecule of sugar has 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.
Explanation:
hope this helps
what is fractional distillation what is fractional distillation explain it with the help of an activity
Answer:
Fractional distillation is a method for separating liquids with different boiling points. For example, liquid ethanol can be separated from a mixture of ethanol and water by fractional distillation. ... The boiling point of ethanol is 78°C and the boiling point of water is 100°C.
What is the molarity of a solution of 10% by mass cadmium sulfate, CdSO4 (molar mass = 208.46 g/mol) by mass? The density of the solution is 1.10 g/mL.
a. 0.528 M
b. 0.436 M
c. 0.479 M
d. 0.048 M
e. 22.9 M
Answer:
a. 0.528 M .
Explanation:
Hello!
In this case, since the given by-mass percent can be written as:
[tex]\frac{10gCdSO_4}{100g\ sol}[/tex]
By using the density and molar mass of the solute, cadmium sulfate, we can compute the molarity, by also making sure we convert from mL to L of solution:
[tex]M=\frac{10gCdSO_4}{100g\ sol}*\frac{1molCdSO_4}{208.46gCdSO_4} *\frac{1.10g\ sol}{1mL\ sol}*\frac{1000mL}{1L} \\\\ M=0.528M[/tex]
Thereby, the answer is a. 0.528 M .
Best regards.
The molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.
To calculate molarity we need to find out how many moles of CdSO4 are present in the solution.
Given:
Mass of [tex]CdSO_4[/tex]= 10% by mass of the solutionMolar mass of [tex]CdSO_4[/tex] = 208.46 g/molDensity of the solution = 1.10 g/mLWe need to calculate the mass of [tex]CdSO_4[/tex]:
Mass of [tex]CdSO_4[/tex] = (10% / 100%) * Total mass of the solution
Mass of [tex]CdSO_4[/tex] = (10 / 100) * 1000 g (since the volume is 1 L, and the density is 1.10 g/mL)
Mass of [tex]CdSO_4[/tex] = 100 g
So, the number of moles of CdSO4:
Number of moles of [tex]CdSO_4[/tex] = Mass of CdSO4 / Molar mass of CdSO4
Number of moles of [tex]CdSO_4[/tex] = 100 g / 208.46 g/mol
Number of moles of [tex]CdSO_4[/tex] ≈ 0.479 moles
Then, we calculate the molarity of the solution:
Molarity = Number of moles of CdSO4 / Volume of the solution (in liters)
Molarity = 0.479 moles / 1 L
Molarity ≈ 0.479 M
Hence, the molarity of the solution of 10% by mass cadmium sulfate [tex](CdSO_4)[/tex] is approximately 0.479 M. The correct option is C.
Learn more about Molarity, here:
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bill nye chemical reactions:
the picture looks cut off but can someone please help!
Answer:
. A(n) _______________________________ is matter that is composed of 2 or more different kinds of atoms.
2. A chemical reaction in which energy is released/given off is _____________________________________.
3. A(n) _________________________________ is a process in which substances are changed into other
substances.
4. Matter that is composed of only 1 kind of atom is a(n) ______________________________.
5. ___________________ is the ability to do work and/or transfer heat.
6. A chemical reaction in which energy is absorbed/taken in is _______________________________.
Knew/New
Write down 3 things you already knew about chemical reactions that were confirmed through watching the
video:
1.
2.
3.
Write down 3 new things that you learned from watching the video:
1.
2.
3.
Episode Guide
1. Chemicals can react to form new _________________________________.
2. Chemical reactions happen when ____________________ hook together.
3. Energy is given off during a chemical reaction because ____________________ are combining with other
__________________________.
4. During the "Try this" experiment, we see the students using vinegar and salt to clean old copper pennies.
The copper gets stripped away and the pennies look new again. Explain why you think this happens.
__________________________________________________________________________________________
Answer Key
compound
exothermic
chemical reaction
element
Energy
endothermic
Answers will vary.
Answers will vary.
chemicals
electrons
electrons
electrons
Copper atoms in the penny react with oxygen atoms from the air & together they form copper oxide which
makes the pennies look dull and dirty. The copper oxide dissolves in a weak acid (the vinegar & salt).
5. When vinegar and baking soda react together, the new substance that is produced is ___________________.
6. _______________ & ______________ are both dangerous by themselves, but when they react together they
form table salt.
7. Pyrotechnician is a name given to people who work to create _________________________.
8. In another experiment, we see kids blow up a balloon by mixing together vinegar and baking soda. When
the kids touch the blown up balloon, it is ____________ to the touch. This means that the reaction is
endothermic or exothermic
9. When someone gets hurt playing sports, often times a cold pack is used for the injury. The cold pack takes
up more energy than it gives off and it gets very ___________ to the touch. This means that the reaction taking
place is endothermic or exothermic
10. How do you know baking a cake is a chemical reaction? ________________________________________
11. There are ___________ naturally occurring elements.
12. If elements are in the same group on the periodic table, what does that tell you? ______________________
__________________________________________________________________________________________
True or False
1. When something burns, heat & light are given off. T or F
2. Your stomach growling is an example of a chemical reaction. T or F
3. Water is 1 part hydrogen and 2 parts oxygen. T or F
4. When baking a cake, a chemical reaction takes place. T or F
5. Everything is made of chemicals. T or F
6. Alfred Nobel invented dynamite. T or F
7. You should always wear safety goggles when working with chemicals. T or F
8. Sodium chloride is better known as sugar. T or F
9. A substance can feel a little warm if the reaction is endothermic. T or F
10. When developing film, red light doesn't affect the picture. T or F
11. A cold pack gets cold because the reaction takes more energy than it gives off. T or F
12. If chemicals behave similarly, they are grouped together on the periodic table. T or F
13. Chemical reactions happen when protons link atoms together. T or F
14. When vinegar and baking soda react, oxygen is produced. T or F
15. Fireworks are not an example of chemical reactions. T or F
carbon dioxide
Sodium chlorine
fireworks
warm
cold
The ingredients (flour, milk, eggs, etc.) are changed
Explanation:
Why was Niels Bohr’s atomic model superior to all the earlier models?
A.
It proved that the atom was indivisible and therefore the smallest unit of matter.
B.
It showed how the electron could orbit the nucleus without falling into it.
C.
It was the first to show that the atom had no net charge.
D.
It used wave behavior to explain the positions of electrons around the nucleus.
Answer:
B
Explanation:
The Niels Bohr's atomic model superior to all the earlier models is because it showed how the electron could orbit the nucleus without falling into it
How can you use density to separate mixtures like sand and small plastic pellets?
Answer:
Slide a magnet through the mixture. When you take the magnet off, the iron filings are going to be attracted to the magnet and the sand will stay in the bowl
Explanation:
Answer:
Density can be used to separate the substances that make up a mixture, because each substance in a mixture has its own density. For example, if a mixture of sand and oil is placed in water, the sand will sink to the bottom of the container. The sand is more dense than the water.
Explanation:
Please mark me as brainy if this helps
A 4.0g Glass was heated from 5°C to 45°C after absorbing 32 J of heat. What is the specific heat of the glass? 
Answer:
[tex]c=0.2\ J/g^{\circ} C[/tex]
Explanation:
Given that,
Mass of a glass, m = 4 g
Initial temperature, [tex]T_i=5^{\circ} C[/tex]
Final temperature, [tex]T_f=45^{\circ} C[/tex]
Heat absorbed, Q = 32 J
We need to find the specific heat of the glass. The formula for the heat absorbed is given by :
[tex]Q=mc\Delta T\\\\c=\dfrac{Q}{m\Delta T}\\\\c=\dfrac{32\ J}{4\ g\times (45-5)^{\circ} C}\\\\=0.2\ J/g^{\circ} C[/tex]
So, the required specific heat of the glass is [tex]0.2\ J/g^{\circ} C[/tex].
How can both the pitcher and the glass contain the same volume of iced
tea?
Answer: $6,600[tex]\alpha \sqrt[n]{x} \lim_{n \to \infty} a_n[/tex]
Explanation:
What would you use to determine whether an acid or alkali has been added to a solution?
A. Reactant
B. Indicator
C. Adjustor
D. Identifier
Answer:
B. Indicator
Explanation:
An indicator is used to determine whether an acid or alkali has been added to a solution.
An acid or alkali changes the hydrogen ion concentration in solution. This is indicated by the pH of the solution after which the acid or alkali has been added.
To see this change, indicators are used. An indicator employs color changes to show a change in chemical properties which pertains to the pH. There are several indicators used which are litmus paper, phenolphthalein, methyl orangehow are Ionic and Covalent Bonds are formed with examples ?
Answer:Comparison of Ionic and Covalent Bonds
In an ionic bond, the atoms are bound together by the electrostatic forces in the attraction between ions of opposite charge. ... For example, sodium (Na), a metal, and chloride (Cl), a nonmetal, form an ionic bond to make NaCl. In a covalent bond, the atoms bond by sharing electrons.
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A 2.26 M solution of KOH is prepared. Calculate the moles and mass of solute present in a 15.2-mL sample of this solution. The molar mass of KOH is 56.11 g/mol.
Answer:
0.0344 moles and 1.93g.
Explanation:
Molarity is defined as the ratio between moles of a solute (In this case, KOH), and the volume. With molarity and volume we can solve the moles of solute. With moles of solute we can find mass of the solute as follows:
Moles KOH:
15.2mL = 0.0152L * (2.26mol / L) = 0.0344moles
Mass KOH:
0.0344 moles * (56.11g/mol) = 1.93g of KOH
if 3.26 g is dissolved in enough water to make exactly 323 ml of solution, what is the molar cocentration of nitrate ion g
H3PO4 what’s the name?
Answer:
Phosphoric acid
Explanation:
Answer:
Phosphoric acid
Explanation:
Phosphoric acid is an oxyacid, which is formed when hydrogen combines with the polyatomic ion phosphate. The polyatomic ion for phosphate is [tex]PO_4^-3[/tex]. To combine this with hydrogen, we "criss-cross" the charges of phosphate (which has a charge of -3) and hydrogen (which has a charge of +1) to get [tex]H_3(PO_4)_1[/tex], the same as [tex]H_3PO_4[/tex].
To answer this question, we essentially reverse these steps. First, we would recognize that this is a hydrogen atom bonded with phosphate. Because phosphate is a polyatomic ion, we know that this is an oxyacid. Because it involves phosphate, we call it phosphoric acid.
I hope this helps!
what is the empirical formula of A compound is found to contain 39.12 % carbon, 8.772 % hydrogen, and 52.11 % oxygen by mass.
Answer:
C₃H₈O₃
Explanation:
Let's assume we have 100 g of said compound. Then we would have:
39.12 g of C8.772 g of H52.11 g of ONow we convert those masses into moles, using their respective atomic weights:
C ⇒ 39.12 g ÷ 12 g/mol = 3.26 mol CH ⇒ 8.722 g ÷ 1 g/mol = 8.722 mol HO ⇒ 52.11 g ÷ 16 g/mol = 3.26 mol OThen we divide those moles by the smallest number among them:
C ⇒ 3.26 mol C / 3.26 = 1H ⇒ 8.722 mol H / 3.26 = 2.68O ⇒ 3.26 mol O / 3.26 = 1Finally we multiply those numbers by 3, so as to convert the 2.68 of H into an integer:
C ⇒ 1 * 3 = 3H ⇒ 2.68 * 3 = 8O ⇒ 1 * 3 = 3Thus the empirical formula is C₃H₈O₃
help please thank you
A chemist prepares a solution of barium acetate BaCH3CO22 by weighing out 52.9g of barium acetate into a 100.mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in /gL of the chemist's barium acetate solution. Round your answer to 3 significant digits.
Answer:
529g/L
Explanation:
The concentration in chemistry is defined as the amount of solute in a determined amount of solution. The concentration in g/L means the amount of grams of solute (In this case, barium acetate), per liter of solution.
To solve this problem we need to find grams of solute (52.9g, already given) and the volume in liters (Converting 100mL to liters):
Volume:
100mL * (1L / 1000mL) = 0.100L
And concentration in g/L is:
52.9g / 0.100L =
529g/LHow do sound waves travel? PLEASE HELP IF YOU WANT BRAINLEIST AND ME TO LIKE URE COMMENT!!
A. Sound causes the air near it to vibrate inwards.
B. waves radiate outward from a central point.
C. Sound moves randomly in different directions.
D. Sound transforms waves into different frequencies.
The answer is A. The vibration caused by the waves through the air eventually weaken, which is why sound diminishes easily over distance.
what is the volume of the rock? if the water rose from 50L to 70mL
What is molarity measured the concentration of
Fungus is an example of a/an-
A:tissue
B:cell type
C:organ
D:organism
Answer:
D.organism
Explanation:
A fungus from the kingdom fungi is an organism
Answer:
D. organism
......................
HELP ME PLEASE
Over time, which cell will look the smallest?
A student places four identical cells into four different
liquids
Cell
cell W
cell x
cell Y
cell z
W:Saltier than the cell
X:Less salty than the cell
Y:Equally as salty as the cell
Z:Pure water with no salts
Answer:
This description can be expressed as follows:
Y > W > XY>W>X
And,
W=ZW=Z
From these expressions we are able to find out that the saltiest cell description is Y, while the less salty is X.
Now, salt is well known as a dehydrating agent. In a process called osmosis cells placed in a salty liquid environment lose water, how?
Well, cells have a semipermeable membrane, in which some substances can get inside. Cells also have water inside. If a cell is placed in a quite salty liquid environment, salt will make the water inside the cells to come out, drying the cell and diminishing its size.
So, in this case, according to the expressions above, Cell Y will look the smallest, while cell X will look the biggest.
If we pour pure water in each liquid, the salt concentration will change and each cell will begin to grow bigger, but the saltiest cell will still be smaller than the others with less salt concentration.
Finally, to answer the question: Y cell will look the smallest after this processThrowing a snowball during snowball fight is most like an example of
Why is your body going through physical and chemical changes?
Answer:
Physical and chemical changes can occur almost everywhere, even in our bodies! Food must be broken down into a form that our cells can use. When we eat, our bodies physically break down food into small pieces. Our bodies also chemically break down those small pieces of food into tiny organic molecules.
Explanation:
3
Directions: Drag each tile to the correct box.
Three phases of waler are shown below.
Put the phases in order from fastest particle molion to slowest particle molion.
liquid water
>
steam
ice
Reset
Submit
Answer:
In order from fastest to slowest, Steam > Liquid Water > Ice
Explanation:
As temperatures rise, particles are allowed to move faster and more freely. If you think about the phases of matter, the more compact something is (solids), the less the particles are able to move. Taking the temperate of ice into consideration, the cold further restricts fast movement of particles, whereas gas (especially steam in this case), in hot temperatures, is able to move quickly and freely in the atmosphere.