NEET Some Basic Concepts Of Chemistry — Set 4

Question 1

What volume of $ \ce{CO2} $ at STP is produced when 10 g of $ \ce{C2H2} $ is burned completely? (Molar mass: $ \ce{C2H2} $ = 26 g/mol)

Accepted Answer

Reaction: $ \ce{2C2H2 + 5O2 -> 4CO2 + 2H2O} $. Moles of $ \ce{C2H2} $ = $ \frac{10}{26} $ ≈ 0.3846 mol. 2 mol $ \ce{C2H2} $ produce 4 mol $ \ce{CO2} $; 0.3846 mol produce 0.7692 mol. Volume = 0.7692 × 22.4 ≈ 17.23 L.

Question 2

A 3 M solution of $ \ce{NaCl} $ has a density of 1.25 g/mL. What is its molality? (Molar mass of $ \ce{NaCl} $ = 58.5 g/mol)

Accepted Answer

Mass of 1 L solution = 1000 × 1.25 = 1250 g. Mass of $ \ce{NaCl} $ = 3 × 58.5 = 175.5 g. Mass of water = 1250 - 175.5 = 1074.5 g = 1.0745 kg. Molality = $ \frac{3}{1.0745} $ ≈ 2.79 m.

Question 3

What is the mass of $ \ce{AgCl} $ produced when 17 g of $ \ce{AgNO3} $ reacts with excess $ \ce{NaCl} $? (Molar masses: $ \ce{AgNO3} $ = 170 g/mol, $ \ce{AgCl} $ = 143.5 g/mol)

Accepted Answer

Reaction: $ \ce{AgNO3 + NaCl -> AgCl + NaNO3} $. Moles of $ \ce{AgNO3} $ = $ \frac{17}{170} $ = 0.1 mol. 1 mol $ \ce{AgNO3} $ produces 1 mol $ \ce{AgCl} $; mass = 0.1 × 143.5 = 14.35 g.

NEET Chemistry: Some Basic Concepts Of Chemistry — Practice Set 4

Q1. What volume of \( \ce{CO2} \) at STP is produced when 10 g of \( \ce{C2H2} \) is burned completely? (Molar mass: \( \ce{C2H2} \) = 26 g/mol)

Q2. A 3 M solution of \( \ce{NaCl} \) has a density of 1.25 g/mL. What is its molality? (Molar mass of \( \ce{NaCl} \) = 58.5 g/mol)

Q3. What is the mass of \( \ce{AgCl} \) produced when 17 g of \( \ce{AgNO3} \) reacts with excess \( \ce{NaCl} \)? (Molar masses: \( \ce{AgNO3} \) = 170 g/mol, \( \ce{AgCl} \) = 143.5 g/mol)

Q4. How many grams of \( \ce{KMnO4} \) are required to oxidize 9.8 g of \( \ce{FeSO4} \) in acidic medium to \( \ce{Fe2(SO4)3} \)? (Molar masses: \( \ce{KMnO4} \) = 158 g/mol, \( \ce{FeSO4} \) = 152 g/mol)

Q5. A solution of \( \ce{H2SO4} \) has a molarity of 0.5 M and a density of 1.02 g/mL. What is its molality? (Molar mass: \( \ce{H2SO4} \) = 98 g/mol)

Q6. What is the mass percentage of \( \ce{NH3} \) in a solution made by dissolving 3.4 g of \( \ce{NH3} \) in 16.6 g of water? (Molar mass: \( \ce{NH3} \) = 17 g/mol)

Q7. A 500 mL solution of \( \ce{H2SO4} \) has a molarity of 0.2 M and density 1.02 g/mL. What is the mass percentage of \( \ce{H2SO4} \)? (Molar mass: \( \ce{H2SO4} \) = 98 g/mol)

Q8. A mixture of 6 g \( \ce{H2} \) and 44 g \( \ce{O2} \) is ignited to form \( \ce{H2O} \). What is the mass of \( \ce{H2O} \) produced? (Atomic masses: H = 1, O = 16)

Q9. How many grams of \( \ce{Zn} \) are required to produce 2.24 L of \( \ce{H2} \) at STP with excess \( \ce{H2SO4} \)? (Atomic mass: Zn = 65)

Q10. How many grams of \( \ce{Na2CO3} \) are required to produce 8.4 g of \( \ce{NaCl} \) with excess \( \ce{HCl} \)? (Molar masses: \( \ce{Na2CO3} \) = 106 g/mol, \( \ce{NaCl} \) = 58.5 g/mol)