Observations That Helps Determine Chemical Reaction
Trending Questions
Q. When washing soda is treated with hydrochloric acid, it gives off colourless gas with lot of effervescence, then that gas is
- CO2
- O2
- CO
- Cl2
Q.
Why does photographic films get spoilt when exposed to sunlight? Give an equation to support your answer.
Q.
On heating sodium hydrogen carbonate, it decomposes to form sodium carbonate, water and oxygen.
True
False
Q.
Why does a photographic film get spoilt if exposed to sunlight? Give an equation in support of your answer.
Q. White silver chloride in sunlight turns to
- red
- grey
- yellow
- remain white
Q. Which amongst the following observations does not indicate that a chemical reaction has occurred?
- Formation of a precipitate
- Change in total mass of substance
- Evolution of heat and light
- Production of gas
Q.
Which of the following observations helps to determine whether a chemical reaction has taken place or not?
(i) Change in state.
(ii) Change in colour.
(iii) Change in shape
(iv) Evolution of gas.
(v) Change in temperature.
(ii), (iii), (iv), (v)
(i), (ii), (iv), (v)
(i), (ii), (iii), (v)
(iii), (v)
Q. Which of these suggest that a chemical reaction may be occurring?
- Change of colour
- Change of state
- Reduction of temperature
- Release of a gas
Q. Observing the changes, in which of the following would you say a chemical reaction may be occurring?
(i) Heating iodine changes the colour from bluish black to purple
(ii) Mixing ammonia and hydrogen chloride gases gives fumes containing a white powdery substance
(iii) Mixing an acid and a base solution raises the temperature.
(iv) Mixing ferrous sulphide and hydrochloric acid gives off a gas with a rotten egg smell
(i) Heating iodine changes the colour from bluish black to purple
(ii) Mixing ammonia and hydrogen chloride gases gives fumes containing a white powdery substance
(iii) Mixing an acid and a base solution raises the temperature.
(iv) Mixing ferrous sulphide and hydrochloric acid gives off a gas with a rotten egg smell
- (i), (ii), (iv)
- (ii), (iii), (iv)
- (i), (ii), (iii), (iv)
- (i), (ii), (iii)