Ma'am its a MCQ.
1) What is the colour of gases produced on thermal decomposition of ferrous sulphate?
  (a)greenish yellow
  (b)yellow
  (c)reddish yellow
  (d)colourless
 
2) A student test a sample of drinking water and found its pH as 6. Which of the following have been possibly present in water?
  (a)sodium hydroxide
  (b)sodium chloride
  (c)sodium bicarbonate
  (d)sodium carbonate
 Its a physics question.
3) While experimentally verifying Ohm's law a student observed that the pointer of the voltmeter coincide with 15th division when the voltmeter has a least count of 0.05 V. Find the observed reading of voltmeter.

Asked by Kalita Padmanath | 29th Sep, 2014, 11:02: AM

Expert Answer:

Dear kalitapadmanath@yahoo.in

Thanks for asking us a question in Ask the Expert section of TopperLearning.com.

Answer to 1st MCQ is colourless. As gases released during the process are SO2 and SO3 which are colourless.

In case of second MCQ:

One of the options must be an acid or the compound which will lower down the pH.

Option (a): Sodium hydroxide is basic in nature, if it is present in water then pH will be more than 7.

Option (b): Sodium chloride is neutral in nature which also will NOT affect the pH.

Option (c) Sodium bicarbonate and (d) Sodium carbonate are basic in nature so here also pH will be more than 7.

Regards

Topperlearning Team.

Answered by Arvind Diwale | 29th Sep, 2014, 06:51: PM