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प्रश्न
Match the following physical quantities with units
| Physical quantity | Unit |
| (i) Molarity | (a) g mL–1 |
| (ii) Mole fraction | (b) mol |
| (iii) Mole | (c) Pascal |
| (iv) Molality | (d) Unitless |
| (v) Pressure | (e) mol L–1 |
| (vi) Luminous intensity | (f) Candela |
| (vii) Density | (g) mol kg–1 |
| (viii) Mass | (h) Nm–1 |
| (i) kg |
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उत्तर
| Physical quantity | Unit |
| (i) Molarity | (e) mol L–1 |
| (ii) Mole fraction | (d) Unitless |
| (iii) Mole | (b) mol |
| (iv) Molality | (g) mol kg–1 |
| (v) Pressure | (c) Pascal |
| (vi) Luminous intensity | (f) Candela |
| (vii) Density | (a) g mL–1 |
| (viii) Mass | (i) kg |
Explanation:
(i) It is defined as the number of moles of solute dissolved in 1 litre of solution. So, the unit of molarity is mol L–1
(ii) Mole fraction is defined as the number of moles of a constituent divided by the total number of moles. So, it is unitless.
(iii) Mole is the unit to measure the amount of an atom or molecule in \[\ce{SI}\] system. it is symbolized as "mol".
(iv) It is defined as the number of moles of solute dissolved in 1 kg of solvent. so, the unit of morality is mol kg–1.
(v) It is defined as the force per unit area. so, the unit of pressure is Pascal.
(vi) It is the amount of visible light released per unit solid angle in unit time. so, it's unit will ve candela.
(vii) It is defined as the mass of a substance (in kg) divided by the volume of that substance (in mL). The unit of density is g mL–1.
(viii) Mass is used to measure the amount of a substance or an object. The unit of mass is kg.
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