These are 6 questions and 6 answers.
Question 1:
Answer: 33.7 atm
Explanation:
1) Data:
p=?
m = 1360.0 g N2O
V = 25.0 liter
T = 59.0°C
2) Formulas:
Ideal gas law: p V = n R T
n = mass in grams / molar mass
3) Solution
n = mass of N2O in grams / molar mass of N2O
molar mass of N2O = 2 * 14 g/mol + 16 g/mol = 44 g/mol
n = 1360.0 g / 44 g/mol = 30.9 mol
T = 59.0 + 273.15 K = 332.15 K
R = 0.0821 atm*liter / K*mol
=> p = nRT / V = 30.9 mol * 0.0821 [atm*liter / K * mol] * 332.15K / 25.0 liter = 33.7 atm
Answer: 33.7 atm
Question 2:
Answer: 204.5 liter
Explanaton:
1) Data:
m = 11.7 g of He
V = ?
p = 0.262 atm
T = - 50.0 °C
2) Formulas:
pV = nRT
n = mass in grams / atomic mass
3) Solution:
atomic mass of He = 4.00 g/mol
n = 11.7 g / 4.00 g/mol = 2.925 mol
T = - 50.0 + 273.15 K = 223.15 K
pV = nRT => V = nRT / p
V = 2.925 mol * 0.0821 [* liter / K*mol] *223.15K / 0.262 atm = 204.5 liter
Answer: 204.5 liter
Question 3.
Answer: 97.8 mol
Explanation:
1) Data:
Ethane
T = 15.0 °C
p = 100.0 kPa
V = 245.0 ml
n = ?
2) Formula
pV = nRT
3) Solution
pV = nRT => n = RT / pV
T = 15.0 + 273.15K = 288.15K
R = 8.314 liter * kPa / (mol*K)
n = 8.314 liter * kPa / (mol*K) * 288.15K / [100.0 kPa * 0.245 liter] = 97.8 mol
Answer: 97.8 mol
Question 4:
Answer: 113.67 K = - 159.48 °C
Explanation:
1) Data:
V = 629 ml of O2
p = 0.500 atm
n = 0.0337 moles
T = ?
2) Formula:
pV = nRT
3) Solution:
pV = nRT => T = pV / (nR)
T = 0.500 atm * 0.629 liter / (0.0337 mol * 0.0821 atm*liter/K*mol ) = 113.67 K
°C = T - 273.15 = - 159.48 °C
Question 5.
Answer: 5.61 g
Explanation:
1) Data:
V = 3.75 liter of NO
T = 19.0 °C
p = 1.10 atm
m = ?
2) Formulas
pV = nRT
mass = number of moles * molar mass
3) Solution:
pV = nRT => n = pV / (RT)
T = 19.0 + 273.15 K = 292.15 K
n = 1.10 atm * 3.75 liter / [ (0.0821 atm*liter / K*mol) * 292.15 K ] = 0.17 mol
molar mass of NO = 17.0 g/mol + 16.0 g/mol = 33.0 g/mol
mass = 0.17 mol * 33.0 g/mol = 5.61 g
Question 6:
Answer: 22.4 liter
Explanation:
1) Data:
STP
n = 1.00 mol
V = ?
Solution:
1) It is a notable result that 1 mol of gas at STP occupies a volume of 22.4 liter, so that is the answer.
2) You can calculate that from the formula pV = nRT
3) STP stands for stantard pressure and temperature. That is p = 1 atm and T = 0°C = 273.15 K
4) Clear V from the formula:
V = nRT / p = 1.00 mol * 0.0821 atm*liter / (K*mol) * 273.15 K / 1.00 atm = 22.4 liter
Answer : The concentration of the
is, 0.115 M
Explanation :
Using dilution law,

where,
= basicity of an acid = 1
= acidity of a base = 1
= concentration of
= 0.125 M
= concentration of KOH = ?
= volume of
= 25 ml
= volume of NaOH = 27.07 ml
Now put all the given values in the above law, we get the concentration of the
.


Therefore, the concentration of the
is, 0.115 M
Initially, you should know that what the text describes is a test used to analyze and identify some metal ions in a compound. This is the principle behind it: first the ions are excited, by the heat of the flame, they absorb energy and the electrons are promoted to higher energy levels; after this, the electrons will fall back down to lower energy levels releasing energy as light. The flame color that is seen is related with the frequency of the light emitted.
Here is the text with the right words.
In this experiment, the metal cations in the solutions were initially in
the ground state. When placed in the flame, the metals then (absorbed)
energy as (heat). When this occurred,
electrons made transitions from (low) energy levels to (high)
energy levels. The metals were then in the (excited) state. The
electrons in these metals then made transitions from (high) energy
levels to (low) energy levels, resulting in the (emission) of energy as (EM radiation).
Answer:
is the correct choice that is option A.
Explanation:
An electron has
times the mass of a proton, but an equal and opposite negative charge.
Lets
is any element represented here.
Where
is the number of protons as well as its atomic number.
And
is the mass number which is the number of protons and neutrons in any atom.
Note: We know that Hydrogen
is devoid of neutron,so number of neutrons in a Hydrogen atom is zero.
Then
is also a representation of single proton.
So
is the right choice that is option A.