Units and Dimensions

Q. What will be the molarity of a solution containing 5 g of sodium hydroxide in 250 mL of water?

1. 0.5 M
2. 1.0 M
3. 2.0 M
4. 0.1 M

Q. $1\text{amu}$ is equal to:

1. $\frac{1}{{12}^{\text{th}}}$ the mass of one $C-12$ atom
2. $1\text{g}$ of $H_2$
3. $\frac{1}{{14}^{\text{th}}}$ the mass of one $O-16$ atom
4. $1.66\times {10}^{-23}\text{kg}$

Q. Find the number of moles of $MgS{O}_4.7H_{2}O$ in a pure sample that contains 0.0022 moles of oxygen atoms.

1. 0.2 moles
2. 0.002 moles
3. 0.2 millimoles
4. 2 moles

Q.

The value of $8.0km$ in inches is

(1 m = 1.094 yards & 1 yard = 36 inches)

1. $3.15\times {10}^5$
2. $3.2\times {10}^5$
3. $3.1\times {10}^5$
4. $3.3\times {10}^5$

Q.

What is the value of 500 Mg in kilogram?

1. 5 $\times$ ${10}^6$ kg

2. 5 $\times$ ${10}^5$ kg

3. 5 $\times$ ${10}^7$ kg

4. 5 $\times$ ${10}^4$ kg

Q.

What is the value of 4 days in seconds?

1. 354600 s

2. 345600 s

3. 364500 s

4. None

Q. A fixed mass of an ideal gas contained in a 24.63 L sealed rigid vessel at 1 atm is heated from $-{73}^{\circ }\text{C}$ to ${27}^{\circ }\text{C}$. Calculate the change in Gibbs energy if the entropy of the gas is a function of temperature given as, $S=2+{10}^{-2}\text{T (J/K)}:(\text{Use 1 atm - L = 0.1 kJ}$)

1. $1231.5\text{J}$
2. $1281.5\text{J}$
3. $781.50\text{J}$
4. $0\text{J}$