MTTC MTTC Chemistry 2

Question 1

In the reaction 2H₂ + O₂ → 2H₂O, how many moles of water are produced from 4 moles of H₂?

Accepted Answer

4

Answer

The molar ratio of H₂ to H₂O is 2:2 (1:1), so 4 moles of H₂ produces 4 moles of H₂O.

Question 2

What is the molarity of a solution prepared by dissolving 2 moles of NaCl in enough water to make 500 mL of solution?

Accepted Answer

4 M

Answer

Molarity = moles ÷ liters = 2 mol ÷ 0.5 L = 4 M.

Question 3

According to Le Chatelier's principle, if pressure is increased on a gaseous equilibrium system, the reaction shifts toward:

Accepted Answer

The side with fewer moles of gas

Answer

Increasing pressure shifts equilibrium toward the side with fewer moles of gas to partially relieve the stress.

Question 4

Which type of chemical reaction is represented by: A + BC → AC + B?

Accepted Answer

Single replacement

Answer

This is a single replacement reaction where element A displaces element B from compound BC.

Question 5

What is the standard enthalpy of formation (ΔHf°) for a pure element in its most stable state at standard conditions?

Accepted Answer

0 kJ/mol

Answer

By definition, the standard enthalpy of formation for any element in its most stable form at standard conditions is exactly zero.

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