31
Q:

Mg+O2=MgO

Balance the above Chemical equation?

A) 2Mg + O2 ----> 2MgO B) 2Mg + O ----> 2MgO
C) 2Mg + O ----> MgO2 D) 2Mg + O2 ----> MgO2

Answer:   A) 2Mg + O2 ----> 2MgO



Explanation:

Given Equation is 

Mg + O2  MgO

Balancing the Chemical Equation is nothing but Conservation of Matter. As Matter is Neither created nor Destroyed, it must be conserved.

Here we have 1 Mg and 2 O on the left side and 1 Mg and 1 O on the right side

To balance that, add 1 Mg on the left side so that it becomes 2 Mg and 2 O on the left side

i.e,

2 Mg + O2  2 MgO

Here it has 2 Mg & 2 O on the left side and 2 Mg and 2 O on the right side and the Chemical equation is Balanced.

Subject: Chemistry
Exam Prep: GATE , AIEEE
Job Role: Analyst
Q:

The percentage of nitrogen in the air is about

A) 74% B) 76%
C) 78% D) 80%
 
Answer & Explanation Answer: C) 78%

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9 940
Q:

Methane contributes towards global warming so it is called a _________________ gas.

 

A) poisonous B) carcinogenic
C) infectious D) greenhouse
 
Answer & Explanation Answer: D) greenhouse

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2 36588
Q:

Which of the following is a metal?

 

A) Sulphur B) Nitrogen
C) Oxygen D) No option is correct
 
Answer & Explanation Answer: D) No option is correct

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1 14450
Q:

Which of the following group is NOT Dobereiner Triads?

 

A) Li, Na, K B) N, P Au
C) Cl, Br, I D) Ca, Sr, Ba
 
Answer & Explanation Answer: B) N, P Au

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4 54789
Q:

Safety matches contain

A) Sulphur B) Phosphorus
C) Magnesium D) Potassium
 
Answer & Explanation Answer: B) Phosphorus

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3 921
Q:

Air ___________________ are the substances which contaminate the air.

A) Reactants B) Irritants
C) Resistants D) Pollutants
 
Answer & Explanation Answer: D) Pollutants

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3 907
Q:

By using which foam the Researchers from Indian Institute of Technology – Bombay have made a low cost piezo resistive vibration sensor?

A) Only Polyurethane B) Only Polyethylene
C) Both Polyurethane and Polyethylene D) Neither Poly urethane nor Polyethylene
 
Answer & Explanation Answer: B) Only Polyethylene

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5 938
Q:

Which of the following is NOT a compound?

 

A) Ammonia B) Milk
C) Sodiumchloride D) Chalk
 
Answer & Explanation Answer: B) Milk

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