HC Semester Exam

Front

What is the balanced equation for the reaction between NaOH and CaCl₂?

Back

The balanced equation is 2NaOH(aq) + CaCl₂(aq) → Ca(OH)₂(s) + 2NaCl(aq).

Front

What is the coefficient for NaOH when balancing the equation NaOH + CaCl₂ → Ca(OH)₂ + NaCl?

Back

The coefficient for NaOH is 2.

Front

How many moles of water are produced when 2 moles of hydrogen react with oxygen?

Back

2 moles of water are produced.

Front

What is the mole ratio of H₂ to O₂ in the reaction 2H₂ + O₂ → 2H₂O?

Back

The mole ratio is 2:1.

Front

If 8 moles of H₂ are used, how many moles of O₂ are consumed?

Back

4 moles of O₂ are consumed.

Front

Define a mole in chemistry.

Back

A mole is a unit that measures the amount of substance, defined as 6.022 x 10²³ particles (atoms, molecules, etc.).

Front

What is the significance of balancing chemical equations?

Back

Balancing chemical equations ensures that the law of conservation of mass is obeyed, meaning the number of atoms of each element is the same on both sides of the equation.

Front

What does (aq) signify in a chemical equation?

Back

(aq) signifies that the substance is dissolved in water, indicating an aqueous solution.

Front

What is the product formed when NaOH reacts with CaCl₂?

Back

The product formed is Ca(OH)₂, which is a solid precipitate.

Front

What is a precipitate in a chemical reaction?

Back

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.