NEET Some Basic Concepts Of Chemistry — Set 8

Question 1

How many grams of $ \ce{MgCO3} $ are required to produce 4.4 g of $ \ce{CO2} $ with excess $ \ce{HCl} $? (Molar masses: $ \ce{MgCO3} $ = 84 g/mol, $ \ce{CO2} $ = 44 g/mol)

Accepted Answer

Reaction: $ \ce{MgCO3 + 2HCl -> MgCl2 + CO2 + H2O} $. Moles of $ \ce{CO2} $ = $ \frac{4.4}{44} $ = 0.1 mol. 1 mol $ \ce{CO2} $ from 1 mol $ \ce{MgCO3} $; mass = 0.1 × 84 = 8.4 g.

Question 2

A mixture of 16 g $ \ce{CH4} $ and 32 g $ \ce{O2} $ is ignited. What is the mass of $ \ce{CO2} $ produced? (Atomic masses: C = 12, H = 1, O = 16)

Accepted Answer

Reaction: $ \ce{CH4 + 2O2 -> CO2 + 2H2O} $. Moles: $ \ce{CH4} $ = $ \frac{16}{16} $ = 1 mol, $ \ce{O2} $ = $ \frac{32}{32} $ = 1 mol. 1 mol $ \ce{CH4} $ needs 2 mol $ \ce{O2} $; $ \ce{O2} $ is limiting (1 mol). 0.5 mol $ \ce{CH4} $ reacts, producing 0.5 mol $ \ce{CO2} $ = 22 g.

Question 3

A 0.5 M $ \ce{HNO3} $ solution is diluted from 100 mL to 400 mL. What is the final molarity?

Accepted Answer

$ M_1 V_1 = M_2 V_2 $. 0.5 × 100 = $ M_2 $ × 400. $ M_2 = \frac{0.5 \times 100}{400} = 0.125 $ M.

NEET Chemistry: Some Basic Concepts Of Chemistry — Practice Set 8

Q1. How many grams of \( \ce{MgCO3} \) are required to produce 4.4 g of \( \ce{CO2} \) with excess \( \ce{HCl} \)? (Molar masses: \( \ce{MgCO3} \) = 84 g/mol, \( \ce{CO2} \) = 44 g/mol)

Q2. A mixture of 16 g \( \ce{CH4} \) and 32 g \( \ce{O2} \) is ignited. What is the mass of \( \ce{CO2} \) produced? (Atomic masses: C = 12, H = 1, O = 16)

Q3. A 0.5 M \( \ce{HNO3} \) solution is diluted from 100 mL to 400 mL. What is the final molarity?

Q4. How many significant figures are present in the result of \( \frac{0.0456 \times 298.15}{0.112} \)?

Q5. A mixture of 12 g \( \ce{C} \) and 40 g \( \ce{O2} \) is ignited to form \( \ce{CO2} \) and \( \ce{CO} \). If 22 g of \( \ce{CO2} \) is produced, what is the mass of \( \ce{CO} \) formed? (Atomic masses: C = 12, O = 16)

Q6. How many grams of \( \ce{NaOH} \) are required to produce 14.6 g of \( \ce{NaNO3} \) with excess \( \ce{HNO3} \)? (Molar masses: \( \ce{NaOH} \) = 40 g/mol, \( \ce{NaNO3} \) = 85 g/mol)

Q7. How many grams of \( \ce{MnO2} \) are required to produce 1.42 g of \( \ce{Cl2} \) with excess \( \ce{HCl} \)? (Molar masses: \( \ce{MnO2} \) = 87 g/mol, \( \ce{Cl2} \) = 71 g/mol)

Q8. A solution of \( \ce{KOH} \) has a molarity of 1.5 M and a density of 1.05 g/mL. What is its molality? (Molar mass: \( \ce{KOH} \) = 56 g/mol)

Q9. What is the mass of \( \ce{AgNO3} \) produced when 14.3 g of \( \ce{AgCl} \) reacts with excess \( \ce{HNO3} \)? (Molar masses: \( \ce{AgCl} \) = 143.5 g/mol, \( \ce{AgNO3} \) = 170 g/mol)

Q10. How many grams of \( \ce{Fe2O3} \) are required to produce 11.2 g of \( \ce{Fe} \) with excess \( \ce{CO} \)? (Molar masses: \( \ce{Fe2O3} \) = 160 g/mol, Fe = 56 g/mol)