Question

1.A reaction that releases energy from the system in the form of heat is called [ ] a)endothermic b)exothermic c)physical change d)none 2.A reaction that the system absorb energy from its surroundings in the form of heat is called [ ] a)exothermic b)endothermic c)both a&b c) none 3.neutralisation reaction is example of— reaction [ ] a)slow reaction b)fast reaction c)exothermic d)both b&c 4.photosynthesis is an example of— reaction [ ] a)exothermic b)instantaneous reaction c)decomposition d)endothermic 5.Respiration is an example of— reaction [ ] a)endothermic b)exothermic c)very slow reaction d)all 6.which of the following is dry ice [ ] a)solid SO2 b)liquid CO c)solid CO2d)none 7.solution of sulphuric acid in to water is an example of—reaction [ ] a)double combination b)slow reaction c)exothermic reaction d)moderate reaction 8.which of the following is exothermic reaction [] a)photosynthesis b) boiling c)melting ice d)nuclear fission 9.—reaction energy in the form of heat [ ] a)exothermic b)endothermic c)both a&b d)none 10.which of the following is endothermic reaction [ ] a)neutralisation b)respiration reaction c)combustion reaction d)photosynthesis

Answer 1

Explanation:

Combustion: The burning of carbon-containing compounds uses oxygen, from air, and produces carbon dioxide, water, and lots of heat. For example, combustion of methane (\text{CH}_4CH

4

start text, C, H, end text, start subscript, 4, end subscript) can be represented as follows:

CH4 + 2(O2) ---> CO2 + 2H2O + heat

CH4 + 2(O2) ---> CO2 + 2H2O + heat

2) Rain: Condensation of water vapor into rain releasing energy in the form of heat is an example of an exothermic process.