Answer:
question 1:
The right choice is → c. KNO₃
question 2:
The right choice is → c. 784 mm Hg
Explanation:
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question 1:
From the figure, the solubility of the different salts at 90 °C is:
NaCl:
It is 40 g per 100 g water.
KBr:
It is 100 g per 100 g water.
KNO₃:
It is about 240 g per 100 g water.
NaClO₃:
It is about 220 g per 100 g water.
∴ The most soluble salt in water at 90°C is KNO₃.
So, the right choice is
→ c. KNO₃
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question 2:
We can use the general law of ideal gas: PV = nRT.
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and T are constant, and have two different values of P and V:
P₁ * V₁= P₂ * V₂
from the given data :
P₁ = 3060 mm Hg
V₁ = 0.520 L.
V₂ = 2.03 L.
∴ P₂ = [P₁ * V₁] / V₂ = [3060 mm Hg * 0.520 L] / 2.03 L = 783.84 mm Hg
≅ 784 mm Hg
So, the right choice is
→ c. 784 mm Hg
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