Sawaal

 Chemistry Questions

Popular Latest Rated
Q:

What is the oxidation number of carbon in NaHCO3?

A) -4 B) -3
C) +4 D) +2
 
Answer & Explanation Answer: C) +4

Explanation:

The given compound is NaHCO3 Sodium bicarbonate which is commonly known as Baking soda.

Oxidation numbers are the charges on ions. When a neutral atom loses electrons it becomes positively charged. When a neutral atom gains electrons it becomes negatively charged.

 

Here the C represents the oxidation state of carbon in this compound. Compounds are electrically neutral, which is why we set the sum of the oxidation states equal to zero.

Sodium has a +1 oxidation state. Hydrogen has a +1 oxidation state. Oxygen has a -2 oxidation state. There are three oxygen atoms, which means the total oxidation state provided by both oxygen ions is -6. Adding up these oxidation states we get:

1 + 1 + (-6) + C = 0

-4 + C = 0

=> C = 4


This means the oxidation state of carbon in this compound is +4.

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , GATE
Job Role: Analyst , Bank Clerk , Bank PO

1 5628
Q:

Cathode rays have

A) mass only B) charge only
C) no mass and no charge D) mass and charge both
 
Answer & Explanation Answer: D) mass and charge both

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry

7 5605
Q:

Which combination will produce a precipitate?

A) NaOH (aq) and HCl (aq) B) KOH (aq) and Mg(NO3)2 (aq)
C) NaC2H3O2(aq) and HCl (aq) D) AgNO3(aq) and Ca(C2H2O3) (aq)
 
Answer & Explanation Answer: B) KOH (aq) and Mg(NO3)2 (aq)

Explanation:

In chemistry, a precipitate is an insoluble solid that emerges from a liquid solution. The emergence of the insoluble solid from solution is called precipitation.

Which_combination_will_produce_a_precipitate1558607544.jpg image

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , CAT
Job Role: Analyst

5 5603
Q:

Alloy of copper and zinc is called

A) Bronze B) Gold
C) Silver D) Brass
 
Answer & Explanation Answer: D) Brass

Explanation:

alloy_of_copper_and_zinc_is_called1556100441.jpg image

 

Alloy of copper and zinc is called as Brass.

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: GATE , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk , Analyst

3 5588
Q:

Select the correct statement (s).

A) When energy is transferred to the system from the surrounding as work, the surrounding do work on the system and the value of work (W) positive. B) When energy is transferred from the system to the surrounding as work, work is done on the surrounding and the value of W is negative.
C) Both (A) and (B) D) None of the above
 
Answer & Explanation Answer: C) Both (A) and (B)

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE

13 5508
Q:

Neutron was discovered by

A) J.J.Thomson B) Chadwick
C) Rrutherford D) Priestley
 
Answer & Explanation Answer: B) Chadwick

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry

8 5492
Q:

The element common to all acids is

A) Hydrogen B) Oxygen
C) carbon D) Sulphur
 
Answer & Explanation Answer: A) Hydrogen

Explanation:

Hydrogen is the common element in all acids.

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Analyst , Bank Clerk , Bank PO

4 5449
Q:

A yellow element that stinks when burned

A) Sulphur B) Chlorine
C) Fluorine D) Bromine
 
Answer & Explanation Answer: A) Sulphur

Explanation:

Sulphur is an yellow element that stinks when burned.

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Analyst , Bank Clerk , Bank PO

3 5440