Chemistry NCFE 2018-19 #29-40

Front

What is the number of particles in 1 mole of a substance?

Back

1 mole of a substance contains approximately 6.02 × 10²³ particles, known as Avogadro's number.

Front

What is a chemical reaction?

Back

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another, resulting in the formation of new substances.

Front

What is equilibrium in a chemical reaction?

Back

Equilibrium is the state in which the concentrations of reactants and products remain constant over time, indicating that the forward and reverse reactions occur at the same rate.

Front

How does temperature affect the concentration of products in a reaction?

Back

Increasing temperature generally increases the concentration of products in an endothermic reaction, while decreasing temperature favors the formation of reactants.

Front

What happens to equilibrium when the concentration of a reactant is decreased?

Back

Decreasing the concentration of a reactant shifts the equilibrium position to the left, favoring the formation of reactants.

Front

What is the effect of adding a catalyst to a chemical reaction?

Back

A catalyst speeds up the rate of a chemical reaction without being consumed, but it does not affect the position of equilibrium.

Front

What is the relationship between pressure and equilibrium in gaseous reactions?

Back

Increasing pressure in a gaseous reaction shifts the equilibrium towards the side with fewer moles of gas.

Front

What is the significance of the popping sound in a chemical reaction involving magnesium?

Back

The popping sound indicates that a chemical reaction has occurred, often due to the release of gas or energy.

Front

What is the effect of removing a product from a reaction at equilibrium?

Back

Removing a product shifts the equilibrium to the right, favoring the formation of more products.

Front

What is the definition of STP (Standard Temperature and Pressure)?

Back

STP is defined as a temperature of 0 degrees Celsius (273.15 K) and a pressure of 1 atmosphere (101.3 kPa).