Question

the mass of zinc required to produce 2.24 L of hydrogen gas at STP on treatment with excess of dilute HCl is ?

Answer 1

Answer:

Heating as a transfer of energy

thermal

heat

temperature

In the last chapter we looked at thermal systems. The thermal energy of an object is the amount of energy it has inside of it, in other words, its internal energy. In a thermal system, thermal energy is transferred from one object to another. Heat is the transfer of thermal energy from a system to its surroundings or from one object to another. This transfer of energy is from the object at a higher temperature to the object at a lower temperature.

It is very important to know that, in science, heat and temperature are not the same thing.

Heat is the transfer of thermal energy from a system to its surroundings or from one object to another as a result of a difference in temperature. Heat is measured in joules (J). This is because heat is a transfer of energy.

Temperature is a measure of how hot or cold a substance feels and it is measured in degrees Celsius (°C). Temperature is a measure of the average kinetic energy of the particles in an object or system. We use a thermometer to measure the temperature of an object or substance

Answer 2

Given - Amount of hydrogen gas - 2.24 litre

Find - Mass of zinc required to produce given amount of hydrogen gas.

Solution - The reaction for production of hydrogen gas is -

Zn + 2HCl --> ZnCl2 + H2

In the reaction it is evident that, 1 mole of Zinc produced 1 mole of H2 gas, which at STP will be equal to 22.4 litre.

2.24 litre of hydrogen gas will be produced by - 2.24/22.4 = 0.1 mole

1 mole of Zinc weighs 65.38 g

0.1 mole of Zinc will weigh 6.5 gram.

Hence, 6.5 gram of zinc is required.