Science, asked by drake48, 7 months ago

.Which is not Polyatomic unit

1 point

A phosphorus

B Sulphur

C copper

D hydrogen

2.which one of the following is used as a standard for atomic mass

1 point

A C-12

B C-13

C C-14

D all

3.Relative molecular mass of hydrogen molecule is

1 point

A 1.0078u

B 2.016u

C 35.46u

D 180u

4.Relative atomic mass of calcium and magnesium is

1 point

A 16,40

B 40,16

C 40,24

D 24,16

5.IUPAC

1 point

A International Union for and applied chemistry

B International Union of pure and applied chemistry

C International Union of pure applied and chemistry

D all

6.Concentration of he acid in gastric acid is

1 point

A 0.032M

B 0.043M

C 0.082M

D 0.1M

7.Volum occupied by one mole of any gaseous substance at 273Kand 1 bar pressure is

1 point

A 22.4L

B 24.5L

C 22.7L

D all

8.Gram equivalent mass of hydrochloric acid is

1 point

A 49g/eq

B 36.5g/eq

C 56g/eq

D 31.6g/eq

9.Number of moles present in 46g of ethanol is

1 point

A 3 mole

B 2 mole

C 1 mole

D zero mole

Other:

10.Empirical formula for benzene is

1 point

A HO

B CHO

C CH

D CO

11.Hiw many liter of carbondioxide produce when 32gof methane is completely burnt

1 point

A 22.4L

B 44.8L

C 11.2L

D 44g

12. 11.4L water occupied in steel container it's molar mass is

1 point

A 36g

B 18g

C 9g

D none of these

13. How many mole CaO produced when 100g of calcium carbonate is heated completely

1 point

A 1 mole

B 2 mole

C 3 mole

D zero mole

14.How much volume of chlorine is required to form 36.5g of HCl at 273Kand 1 atmosphere pressure

1 point

A 22.4L

B 11.2L

C 5.6L

D none of these

15. One mole of carbon react with one mole oxygen molecule to form how many mole of carbondioxide

1 point

A 1 mole

B 2 mole

C 3 mole

D 4 mole

16.Hydrogenperoxide (molar mass 34g/mole)its empirical formula HO, which is its whole number

1 point

A 3

B 2

C 1

D 5

17.Sour milk (molar mass 90g/mole) its empirical formula mass 30g it's whole number and name of the compound

1 point

A 2 and acetic acid

B 3 and acetic acid

C 3 and lactic acid

D 2 and lactic acid

18. Gram equivalent mass of sodium hydroxide is

1 point

A 49g/eq

B 56g/eq

C 40g/eq

D 31.6g/eq

19.The number of moles present in 18 g of ethane

1 point

A 0.3M

B 0.6M

C 0.9M

D 1M

20. Which is compound

1 point

A sugar

B carbondioxide

C potassium permanganate

D all

Answers

Answered by sainass329

Answer:

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Answered by vihu14

Answer:

1. In a reaction 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium ethanoate. Show that these observations are in agreement with the law of conservation of mass carbonate.

Ans.

Sodium carbonate + Ethanoic acid → Sodium ethanoate + Carbon dioxide + Water

5.3 g + 6 g → 8.2 g + 2.2 g + 0.9 g

LHS RHS

11.3 g = 11.3 g

(Mass of reactant) (Mass of product)

This shows, that during a chemical reaction mass of reactact = mass of product.

2. Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?

Ans. Ratio of H : O by mass in water is:

Hydrogen : Oxygen → H2O

1 : 8 = 3 : x

x = 8 × 3

∴ 24 g of oxygen gas would be required to react completely with 3 g of hydrogen gas.

3. Which postulate of Dalton's atomic theory the result of the law of conservation of mass?

Ans. The postulate of Dalton's atomic theory that is the result of the law of conservation of mass is-the relative number and kinds of atoms are constant in a given compound. Atoms cannot be created nor destroyed in a chemical reaction.

4. Which postulate of Dalton's atomic theory can explain the law of definite proportions?

Ans. The relative number and kinds of atoms are constant in a given compound.

NCERT TEXTBOOK PAGE 35

1. Define the atomic mass unit.

Ans. One atomic mass unit is equal to exactly one-twelfth (1/12th) the mass of one atom of carbon-12. The relative atomic masses of all elements have been found with respect to an atom of carbon-12.

2. Why is it not possible to see an atom with naked eyes?

Ans. Atom is too small to be seen with naked eyes. It is measured in nanometres.

1 m = 109 nm

NCERT TEXTBOOK PAGE 35

1. Write down the formulae of

(i) Sodium oxide

(ii) Aluminium chloride

(iii) Sodium sulphide

(iv) Magnesium hydroxide

Ans. The formulae. are

(i) Formula bf Sodium Oxide

Symbol → Na O