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Subjective

Match the following physical quantities with units.

	Physical quantity		Unit
A.	Molarity	1.	g ml$$^{-1}$$
B.	Mole fraction	2.	mol
C.	Mole	3.	Pascal
D.	Molality	4.	Unitless
E.	Pressure	5.	mol L$$^{-1}$$
F.	Luminous intensity	6.	Candela
G.	Density	7.	mol kg$$^{-1}$$
H.	Mass	8.	Nm$$^{-1}$$
		9.	kg

Explanation

A. $\rightarrow$ (5)

B. $\rightarrow$ (4)

C. $\rightarrow$ (2)

D. $\rightarrow$ (7)

E. $\rightarrow(3)$

F. $\rightarrow(6)$

G. $\rightarrow$ (1)

H. $\rightarrow$ (9)

$$\begin{gathered} \text { A. Molarity }=\text { concentration in } \mathrm{mol} \mathrm{L}^{-1} \\ \text { Molarity }=\frac{\text { Number of } \mathrm{moles}}{\text { Volume in litres }} \end{gathered}$$

B. Mole fraction = Unitless

C. Mole $=\frac{\text { Mass }(\mathrm{g})}{\text { Molar mass }\left(\mathrm{g} \mathrm{mol}^{-1}\right)}=\mathrm{mol}$

D. Molality $=$ concentration in mol per kg solvent

Molality $=\frac{\text { Number of moles }}{\text { Mass of solvent }(\mathrm{kg})}$

E. The SI unit for pressure is the pascal $(\mathrm{Pa})$, equal to one newton per square metre $\left(\mathrm{N} / \mathrm{m}^2\right.$ or $\left.\mathrm{kg} . \mathrm{m}^{-1} \mathrm{~s}^{-2}\right)$. This special name for the unit was added in 1971; before that, pressure in SI was expressed simply as $\mathrm{N} / \mathrm{m}^2$.

F. Unit of luminous intensity = candela.

The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency $540 \times 10^{\text {12 }}$ hertz and that has a radiant intensity in that direction of $1 / 683$ watt per steradian.

G. Density $=\frac{\text { mass }}{\text { volume }}=\mathrm{g} \mathrm{mL}^{-1}$

H. Unit of mass $=$ kilogram

The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram

MCQ (Single Correct Answer)

Assertion (A) The empirical mass of ethene is half of its molecular mass.

Reason (R) The empirical formula represents the simplest whole number ratio of various atoms present in a compound.

Both $A$ and $R$ are true and $R$ is the correct explanation of $A$.

$A$ is true but $R$ is false.

$A$ is false but $R$ is true.

Both A and R are false.

MCQ (Single Correct Answer)

Assertion (A) One atomic mass unit is defined as one twelfth of the mass of one carbon-12 atom.

Reason (R) Carbon-12 isotope is the most abundant isotope of carbon and has been chosen as standard.

Both $A$ and $R$ are true and $R$ is the correct explanation of $A$.

Both $A$ and $R$ true but $R$ is not the correct explanation of $A$.

$A$ is true but $R$ is false.

Both A and R are false.

MCQ (Single Correct Answer)

Assertion (A) Significant figures for 0.200 is 3 where as for 200 it is 1. Reason (R) Zero at the end or right of a number are significant provided they are not on the right side of the decimal point.

Both $A$ and $R$ are true and $R$ is correct explanation of $A$.

Both $A$ and $R$ are true but $R$ is not the correct explanation of $A$.

$A$ is true but $R$ is false.

Both A and R are false.

MCQ (Single Correct Answer)

Assertion (A) Combustion of 16 g of methane gives 18 g of water. Reason (R) In the combustion of methane, water is one of the products.

Both $A$ and $R$ are true but $R$ is not the correct explanation of $A$.

$A$ is true but $R$ is false.

$A$ is false but $R$ is true.

Both A and R are false.

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