In a titration, you start with 0.05 M sodium hydroxide (NaOH) and slowly add it to 40 mL of HC1 with an unknown concentration. What is the original concentration of the HC1 if you add a total of 15.4 mL of sodium hydroxide to the HC1 to achieve pH =7?
Answer:
The original concentration of the HCl is: 0.01925 M
Explanation:
Equation:
HCl+NaOH-------> NaCl+H₂O
Volume of NaOH added = 0.05 M
No of moles of NaOH = 15.4 mL [tex]x\frac{1 L}{1000 mL} x\frac{0.05 mol NaOH}{L}[/tex]
= 0.00077 mol NaOH
Then,
Volume of HCl solution = 40 mL x 1/1000 mL
= 0.0400 L
Therefore,
Concentration of HCl = 0.00077 mol/0.0400 L
= 0.01925 M
Now, to find the pH:
pH = -log₁₀[H⁺]
= -log₁₀(2x10⁻⁶)
= 5.7
A rigid container filled with a gas is placed in ice (ex. nalgene bottle). What will happen to the pressure of the gas? What do you think will happen to the volume?(Graph)
Explanation:
The pressure will decrease but the volume remains constant
What name is given to the elements that appear in the right-most column of the periodic
table?
- Alkali metals
- Alkaline earth metals
- Transition metals
- Noble gases
(NOBLE GASES IS ANSWERR)
Answer:
Noble gases... (You already know...)
Explanation:
The right-most column of the periodic table contains atoms with full electron shells, also known as Noble Gases.
Hope this helped!
Answer:
Noble gases
Explanation:
The six elements listed in the last column of the table (Group 18) of the periodic table are collectively referred to as the noble gases. All of the noble gases have the maximum number of electrons possible in their outer shells (two electrons in helium’s outer shell, and eight electrons for all the others), making them stable.
Balance the following equations ___Fe + __O2= ___Fe3O4
Which cannot be chemically broken down into simpler substances?
O compound
O element
O solution
O mixture
Answer:
an element.
Explanation:
it is the purest form
Answer:
b
Explanation:
Which of the following belong to a category called the main group of elements
A halogens
B nonmetals
C alkaline metal
D transition elements
Answer:
C. Alkaline Metal ok thanks
Many materials, such as rocks, expand (get larger) when they are heated and contract (shrink) when they are cooled. This change
in size can cause cracks to form and break large rocks into smaller pieces.
In this example, what is caused by heating and cooling?
OA. decay
ОВ.
weathering
OC.
erosion
OD
earthquakes
Answer:
OB: weathering
Explanation:
the cycle of heating and cooling causes stresses called thermal fatigue, this causes the material to break down. In hand, weathering is a physical and chemical process that causes rocks and minerals on the Earth's surface to break down and decompose. Therefore, this matches the process you have described.
Answer:
weathering fun way to imagen it: just imagen u saw ur worst enemie and pretende it is the rock and the wind and ice and water are ur best friends THEN BAM wind and ice and water(ur best friends) make the rock(worst enemie) to dust :D
in which beakers are the particles moving the most slowly
Answer:
A and D
Explanation:
3. Theoretically how many grams of magnesium is required to produce to 5.0 g of
Magnesium oxide?
Answer:
3grams
Explanation:
The reaction for the production of Magnesium dioxide will be
Mg + O2 → MgO
we have 5g of MgO (molar mass 40g)
no of moles of MgO = 5/40 = 0.125
Using unitary method we have
1 mole of Mg require 1 mole of MgO
0.125 Mole of MgO = 0.125mole of Mg
n = given mass /molar mass
0.125 = mass / molar mass
mass = 0.125* 24 = 3grams
Which of these lead (II) salts will dissolve to the greatest extent in water?
a. PbSO4, Ksp = 1.7x10^-8
b. PbI2, Ksp = 6.5x10^-9
c. PbCrO4, Ksp = 1.8x10^-14
d. PbS, Ksp = 2.5x10^-27
e. Pb3(AsO4)2, Ksp = 4.0x10^-36
Answer:
a. PbSO4, Ksp = 1.7x10^-8.
Explanation:
Hello!
In this case, since the solubility product indicates how likely a solid is able to ionize and consequently dissolve in water, we can infer that the larger the solubility product Ksp, the more ions are able dissolve in water; therefore the proper answer goes with the largest Ksp, which is a. PbSO4, Ksp = 1.7x10^-8 since the power goes closer to 1 than the other options.
Best regards!
A solid substance was tested in the laboratory. The test results are listed below: 1.) dissolves in water 2.) is an electrolyte 3.) melts at a high temperature. Based on these results, the solid substance could be
Answer:
NaCl may be i guess so....
A gas at -20c occupies volume 140 ml calculate temperature at which the volume of the gas becomes 65 ml pressure constant
Answer:
–156 °C
Explanation:
The following data were obtained from the question:
Initial temperature (T1) = –20 °C
Initial volume (V1) = 140 mL
Final volume (V2) = 65 mL
Final temperature (T2) =?
Pressure = constant.
Next, we shall convert –20 °C to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Initial temperature (T1) = –20 °C
Initial temperature (T1) = –20 °C + 273 = 253 K.
Next, we shall determine the new temperature of the gas as follow:
Initial temperature (T1) = 253 K
Initial volume (V1) = 140 mL
Final volume (V2) = 65 mL
Final temperature (T2) =?
V1/T1 = V2/T2
140/253 = 65/T2
Cross multiply
140 × T2 = 253 × 65
140 × T2 = 16445
Divide both side by 140
T2 = 16445 /140
T2 = 117 K
Finally, we shall convert 117 K to celcius temperature. This can be obtained as follow:
T(°C) = T(K) – 273
T2 = 117 K
T2 = 117 K – 273
T2 = –156 °C
Thus, the new temperature of the gas is –156 °C
What is the answer? Please
Answer:
Cell
Explanation:
I just passed this unit a month ago.
Answer:
It is 6. Cell
Explanation:
Cells make up the smallest level of a living organism such as yourself and other living things. The cellular level of an organism is where the metabolic processes occur that keep the organism alive. That is why the cell is called the fundamental unit of life.
I really hope this helped. God bless you and have a great day! :-)
If 75J of heat are applied to 8.4 L of a gas at 732 mmHg and 298K, what is the final temperature, in K, of the gas? Cp for an ideal gas is 20.79 J/mol*K.
Answer:
309 K
Explanation:
Step 1: Convert the pressure to atm
We will use the conversion factor 1 atm = 760 mmHg.
732 mmHg × 1 atm/760 mmHg = 0.963 atm
Step 2: Calculate the moles (n) of the ideal gas
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 0.963 atm × 8.4 L/0.0821 atm.L/mol.K × 298 K
n = 0.33 mol
Step 3: Calculate the temperature change
We will use the following expression.
Q = n × Cp × ΔT
ΔT = Q/n × Cp
ΔT = 75 J/0.33 mol × 20.79 J/mol.K
ΔT = 11 K
Step 4: Calculate the final temperature
T = 298 K + 11 K = 309 K
A solution is made by adding 5.01 g of iron sulfate to 75.3 g of water. What is the mass percentage of iron sulfate in this solution?
Answer:
6.24 % of FeSO₄
Explanation:
Solute mass: 5.01 g of FeSO₄
Solvent mass: 75.3 g of water
Solution mass = solute mass + solvent mass
5.01 g + 75.3 g = 80.31 g
We can apply a rule of three. Mass percentage means the mass of solute which is contained in 100 g of solution. Then,
In 80.31 g of solution we have 5.01 g of solute
In 100 g solution, we may have (5.01 . 100)/ 80.31 = 6.24 g of solute.
This is the mass percentage: 6.24%
What are three ways that we can identify when a chemical reaction is occurring?
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Answer:
I play!!!!!!!!
Explanation:
What is the difference between Mega and Milli symbols?
Answer:
Mega = 10^6
Milli = 10^-3
Explanation:
Mega is whatever times 10 to 6th power.
Milli is whatever times 10 to the -3rd power.
how many atoms does sodium hypochlorite have?
Answer:
NaClO; the contained elements ae Na, Cl, O.
How many atoms of phosphorus are in 5.70 mol of copper(II) phosphate?
Answer:
Cu3 (PO4)2 contains a total of 2 atoms of phosphorus in just one molecule. (2.10 mol)(6.02214 x 10^23 atoms / mol)(2 phosphorous) = 2.53 x 10^24 atoms of phosphorous per molecule of copper i
Explanation:
Determine the molarity of a solution prepared by dissolving 0.198 g of "KHP" (C8H5O4K) in enough water to make 125 mL of solution.
When the solution is found and titrated with aqueous sodium hydroxide, the endpoint is reached after the addition of 27.80 mL of base solution. How many moles of NaOH reacted? What is the concentration of the NaOH?
Answer:
0.007756M KHP; 0.0009695 moles NaOH reacts; 0.03488M NaOH.
Explanation:
Potassium hydrogen phthalate, KHP, is a salt used as standard to determine concentration of basic solutions as NaOH solutions.
To find molarity of the KHP solution we need to convert mass of KHP to moles and divide this in 125mL = 0.125L:
Moles KHP -Molar mass: 204.22g/mol-:
0.198g * (1mol / 204.22g) = 0.0009695 moles KHP
Molarity:
0.0009695 moles KHP / 0.125L = 0.007756M KHP
NaOH reacts with KHP as follows:
NaOH + KHP → Na⁺ + KP⁻ + H₂O
That means 1 mole of NaOH reacts per mole of KHP, that means moles of NaOH that reacts are = Moles of KHP added:
0.0009695 moles NaOH reacts
In 27.80mL = 0.02780L the NaOH was contained. Molarity is:
0.0009695 moles NaOH / 0.02780L =
0.03488M NaOH
Moles of NaOH added will be "0.034".
According to the question,
→ [tex]Molarity = \frac{Number \ of \ moles}{Volume}[/tex]
By substituting the values, we get
[tex]= \frac{0.198}{204}\times \frac{1000}{125}[/tex]
[tex]= 0.0077 \ M[/tex]
Let,
The number of moles added be "[tex]M_2[/tex]".Now,
→ [tex]M_1 V_1 = M_2 V_2[/tex]
→ [tex]0.0077\times 125=M_2\times 27.8[/tex]
→ [tex]M_2 = 0.034 \ moles[/tex]
Thus the above answer is appropriate.
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A 50.0 mL solution of Ba(OH)2 is combined with a 150 mL solution of 0.20 M HCl. If the resulting solution has a hydroxide ion concentration of 0.12 M, what was the concentration of Ba(OH)2 in the original solution?
Answer:
0.54M of Ba(OH)2
Explanation:
When Ba(OH)2 reacts with HCl, BaCl2 and H2O are produced as follows:
Ba(OH)2 + 2HCl → BaCl2 + 2H2O
The remanent hydroxide ion is because not all Ba(OH)2 reacts. Thus, we need to find moles of Ba(OH)2 that doesn't react and moles of Ba(OH)2 that reacts. The ratio between total moles and volume of the Ba(OH)2 solution = 0.050L is the molarity of the original solution
Moles of Ba(OH)2 that doesn't react:
50mL + 150mL = 0.200L * (0.12 mol OH- / L) = 0.024 moles OH-
2 moles of OH- are in 1 mole of Ba(OH)2:
0.024 moles OH- * (1mol Ba(OH)2 / 2 mol OH-) = 0.012 moles Ba(OH)2
Moles of Ba(OH)2 that react:
0.150L * (0.20mol / L) = 0.030 moles HCl
2 moles of HCl react per mole of Ba(OH)2:
0.030 moles HCl * (1mol Ba(OH)2 / 2 mol HCl) = 0.015 moles Ba(OH)2
Total moles:
0.012mol + 0.015mol = 0.027mol Ba(OH)2 in 50mL
0.027mol Ba(OH)2 / 0.0500L =
0.54M of Ba(OH)2
Sugar and Salt in water magnetism, state of matter, or solubility?
please help!!!!
Answer:
solubility
Explanation:
Every element in group one has ______________ electron in its outer shell. Every element in group two has _______________ electrons in its outer shell.
need help
Mr. Juan is husband of Maria, before they get married Maria knows that her husband cannot make a baby since he cant produce sperm. But during their 2 years in marriage, Maria got pregnant. Is Juan can file a case to Maria? What it is? Support your answer?
Answer:
yes but first he need to check himself
Explanation:
bcoz if he cannot produce a sperm than she might have cheated him and the baby might be of someone other.
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A weather balloon with a volume of 3.40774 L
is released from Earth’s surface at sea level.
What volume will the balloon occupy at an
altitude of 20.0 km, where the air pressure is
10 kPa?
Answer in units of L.
Answer: The volume occupied at an altitude of 20.0 km is 34.5289 L
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex] (At constant temperature and number of moles)
where,
[tex]P_1[/tex] = initial pressure of gas = 101.325 kPa ( sea level)
[tex]P_2[/tex] = final pressure of gas = 10 kPa
[tex]V_1[/tex] = initial volume of gas = 3.40774 L
[tex]V_2[/tex] = final volume of gas = ?
Now put all the given values in the above equation, we get the final pressure of gas.
[tex]101.325\times 3.40774=10\times V_2[/tex]
[tex]V_2=34.5289L[/tex]
Therefore, the volume occupied at an altitude of 20.0 km is 34.5289 L
Three isotopes of argon occur in nature. Calculate the average atomic mass of argon given the following relative atomic masses and abundances of each of the isotopes.
Isotope Relative Atomic Mass Abundance
Ar-36 35.97 amu 0.337%
Ar-38 37.96 amu 0.063%
Ar-40 39.96 amu 99.600%
a
35.97 amu
b
37.95 amu
c
39.95 amu
d
38.96 amu
Answer:
whats the question
Explanation:
Answer:
Calculate the average atomic mass of argon to two decimal places, given the following relative masses and abundances of each of the isotopes: argon-36 (35.97 amu; 0.337%), argon-38 (37.96 amu; 0.063%), and argon-40 (39.96 amu; 99.600%). ... So the atomic mass of Ar is 0.99639. 96 + 0.0006337. 96 + 0.00337*35.97 = 39.957.
Explanation:
hope this help
Elements in the same period have _____ in common?
-
Answer:
The elements that have the same number of energy levels or the orbitals.
Explanation:
They have he same number -- energy levels
Weathering is a constructive process.
True or false
Answer: true
Explanation: Collection and analysis of data indicates that constructive forces include crustal deformation, faulting, volcanic eruption and deposition of sediment, while destructive forces include weathering and erosion.
The properties of compund are different from the properties of their constituenr
Answer: Atoms of carbon and hydrogen
Explanation: