Mass percentage is another way of expressing concentration of a substance in a mixture. Mass percentage is calculated as the mass of a component divided by the total mass of the mixture, multiplied by 100%. It is calculated as follows:
% CaCO3 = (<span>1.82g of calcium carbonate</span> / (1.05 g SiO2 + 0.69 g of cellulose + <span>1.82g of calcium carbonate)) x 100% = 51.12% Calcium carbonate</span>
Answer:
The molarity of the acid HX is 6.0 M.
Explanation:
We determine the amount of moles of KOH used to neutralize the acid:
=0.12 moles KOH
Then, we calculate the amount of moles of acid:
0.12 moles KOH×
=0.12 moles HX
The molarity of HX is:
=6.0 M
Answer:
-86.02 kJ/ mole
Explanation:
The moles of the acid used = Molarity × Volume (L) =
= 0.50 (0.0372 L)
= 0.0186 moles
The heat released = -1.6 kJ
∴ 0.0186 moles neutralization of HA heat is: -1.6 kJ
The molar heat of neutralization due to one mole of the unknown acid = -1.6/0.0186
= -86.02 kJ/ mole
Answer:
1.73 atm
Explanation:
Given data:
Initial volume of helium = 5.00 L
Final volume of helium = 12.0 L
Final pressure = 0.720 atm
Initial pressure = ?
Solution:
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
P₁ × 5.00 L = 0.720 atm × 12.0 L
P₁ = 8.64 atm. L/5 L
P₁ = 1.73 atm
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