Question

Can any one answer these questions.I will mark as brainliest answer for first answer.

Answer 1

1. Molar mass of CaCO₃ = 40 + 12 + 3 ×16 = 100 g/mol
2.
a)Cation - Cations are positively charged ions.
Example: Na + (sodium)
b)a.m.u : 1 Atomic mass unit is a mass unit is a mass unit equal to exactly 1/12th the mass of 1 atom of C -12.The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus.
Example -

c)Atomicity - It is the no : of atoms in a molecule of an element.
Example - No: of atoms in a molecule of oxygen is 2.

d)Law of constant proportions states that at in a chemical substance , the elements are present in definite proportions by mass.
Example :In H₂0 , always has 2 atoms hydrogen an 1 atom of oxygen , whatever the source of water.

3).No: of moles = Given mass / Molar mass
Given mass = 4 g
Molar mass of CH₄ = 12 + 1 ×4 = 16 g/mol
∴ No: of moles = 4 ÷ 16 = 0.25 moles

4) Molar mass of CO₂ = 12 + 2 × 16 = 44 g / mol
6. 022 × 10²³ moles of Carbon has a mass of 44 g/ mol.
∴
1 mole of CO₂ has a mass of = 44 / 6.022×10²³
2 moles of CO₂ has a mass of = 44 / 6.022×10²³×2 g

5)Robert Whittaker had done the classifications on the basis of:
* Whether they are eukaryotic / prokaryotic.
*Whether they are autographs / heterotrophs.
*Whether they have cell walls / not
*Whether they are multi-cellular / uni - cellular.

The classification proposed by him is :
1.Monera
2.Protista
3.Fungi
4.Plantae
5.Animalia

6)Thrust : Force exerted by an object perpendicular to the surface is called thrust.Its SI Unit is Newton (N).
Pressure : Force exerted by any object per unit area is called pressure.Pressure = Thrust per unit area.Its SI Unit is N/M² Or Pascal.

7)Relative density = density of substance / density of water
19.3 = density of substance /1000 kg/m³
density of substance = 1000 kg/m³×19.3 = 19300 kg/m³



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