Question

1.On burning 10 kg of LPG, 50,000kJ of energy was produced. The calorific value of LPG is (a)5 kJ/g(b)15 kJ/g(c)500kJ/g(d)0.050kJ/g

2.The chemicals present in fire extinguisher are(a)H2SO4+ Na2CO3(b)HCL + NaHCO3(c)H2SO4 + NaHCO3(d)HCl + Na2CO3

3.What is acid rain? How is it caused?

4.A flame always points upwards. Why?

5.It is difficult to burn a heap of green leaves. But dry leaves catch fire easily. Why?

6.Two students A and B heated the same quantity of water in two different parts of the flame. A was able to heat water faster than B. why this happen? Explain with diagram.

7.In an experiment, on burning 3.5 Kg of fuel, 70,000 kJ of energy was produced. Determine its calorific value.

Answer 1

Answer:

3. lt cause of chemical reaction and pollution. acid come from the factory and when volatilization of acid then acid make gas . acid combined with clouds . then acid fall down like rain.