Test : Chemistry - 1


20 Questions MCQ Test NDA (National Defence Academy) Mock Test Series | Test : Chemistry - 1


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This mock test of Test : Chemistry - 1 for Defence helps you for every Defence entrance exam. This contains 20 Multiple Choice Questions for Defence Test : Chemistry - 1 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test : Chemistry - 1 quiz give you a good mix of easy questions and tough questions. Defence students definitely take this Test : Chemistry - 1 exercise for a better result in the exam. You can find other Test : Chemistry - 1 extra questions, long questions & short questions for Defence on EduRev as well by searching above.
QUESTION: 1

Metalloids are

Solution:

Metalloid, a chemical element with properties intermediate between those of typical metals and nonmetals.

QUESTION: 2

Biogas consists of mainly

Solution:

Biogas consists mainly of methane (CH4) and carbon dioxide (CO2). Methane is a valuable form of gas, as it is an efficient energy carrier with a wide range of uses. The amount of CO2 that is produced corresponds to the amount of CO2 captured when the biomass was created.

QUESTION: 3

Alkali metals can -

Solution:

Alkali metals have one electron in their outer shell so alkali metal can easily lose electrons.
 

QUESTION: 4

PH of the human blood is ______.

Solution:

Human Blood pH is regulated to stay within the narrow range of 7.35 to 7.45, making it slightly basic.

QUESTION: 5

Vinegar and Baking Soda together produce ____________.

Solution:

The reaction between baking soda (sodium bicarbonate) and vinegar (dilute acetic acid) generates carbon dioxide gas.

QUESTION: 6

Which one of the following substances is used in the preservation of food stuff? 

Solution:

The chemical formula of Sodium Benzoate is C7H5NaO2. It is widely used as food preservative.

QUESTION: 7

Which one of the following is not an explosive? 

Solution:

Nitro chloroform is not an explosive substance.

QUESTION: 8

What is an endothermic reaction?

Solution:

The term endothermic process describes a process or reaction in which the system absorbs energy in the form of heat.

QUESTION: 9

Adding which substance gives blue colour to glass?

Solution:

Cobalt oxide is added to glass to give it blue color.

QUESTION: 10

Q10. In the following reaction, fill in the blank.Acid + Base → _______ + Water 

Solution:

When an acid and a base are placed together, they react to neutralize the acid and base properties, producing a salt. The H(+) cation of the acid combines with the OH(-) anion of the base to form water.

QUESTION: 11

 The conversion of hard water into soft water by boiling or adding calcium hydroxide is called _______.

Solution:

Clark's method is a process for the large-scale removal of temporary hardness from water. Clark's process involves the addition of a controlled quantity of slaked lime .
 

QUESTION: 12

The atoms, in which the number of protons is same but the number of neutrons is different, are known as- 

Solution:

The Isotopes are a set of nuclides/atoms having the same number of protons, but a different number of neutrons. In other words, the same atomic number having different atomic masses.

QUESTION: 13

Brass gets discolored in air because of the presence of which of the following gases in air?

Solution:

Brass gets discolored because of the presence of Hydrogen Sulphide in air.

QUESTION: 14

Which of the following is used as non-stick coating for cooking utensils?

Solution:

Non-stick cookware is a common application, where the non-stick coating allows food to brown without sticking to the pan. Non-stick is often used to refer to surfaces coated with "Teflon."

QUESTION: 15

Which base is present in lime water?

Solution:

Calcium hydroxide base is present in lime water.

QUESTION: 16

The pH of water at 25° c is 7. When it is heated at 100°C, the pH of water —

Solution:

On heating, the extent of dissociation of water increase which leads to the increase in concentration of H+ ions as well as OH- ions. Hence, the PH of water decreases.

QUESTION: 17

An acid is a substance which —

Solution:

Acids in solution have a pH below 7.0, a sour taste, releases hydroxyl ions in water, turn litmus paper red and accept an electron.

There are two complementary definitions of acids and bases that are important: the Bronsted (or Bronsted-Lowry) definition: an acid is a proton (H+ ion) donor, and a base is a proton acceptor; the Lewis definition: an acid is an electron acceptor, and a base is an electron donor.

QUESTION: 18

With reference to ionic compounds, consider the following statement: 

1. Ionic compounds are insoluble in alcohol

2. Ionic compounds in the solid state are good conductor of electricity

Q. Which of these statements is/are correct?

Solution:

Ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Following the aphorism, \"like dissolves like\", ionic compounds dissolve in polar solvents, especially those that ionize, such as water and ionic liquids. They are usually appreciably soluble in other polar solvents such as alcohols, acetone. Solid ionic compounds cannot conduct electricity because there are no mobile ions or electrons present in the lattice.

QUESTION: 19

Strongest bond is-

Solution:

A triple bond will always be found in a geometrically linear portion of the molecule. While a triple bond is the strongest type of bond, it is not three times stronger than a single bond because pi bonds are weaker than sigma bonds.

QUESTION: 20

The maximum number of hydrogen bonds in a H_2 O molecule is- 

Solution:

In H2O molecule, oxygen has 2 hydrogen attached & 2 lone pair of electrons, so it has tendency to form 4 hydrogen bonds.

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