A U-tube with both ends open to the atmosphere is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a level of \(10~\text{mm}\) above the water level on the other side. Meanwhile, the water rises by \(65~\text{mm}\) from its original level (see diagram). The density of the oil is:
1. \(425~\text{kg m}^{-3}\)
2. \(800~\text{kg m}^{-3}\)
3. \(928~\text{kg m}^{-3}\)
4. \(650~\text{kg m}^{-3}\)
Which of the following statements are correct?
(a) | centre of mass of a body always coincides with the centre of gravity of the body . |
(b) | centre of gravity of a body is the point about which the total gravitational torque on the body is zero. |
(c) | a couple on a body produce both translational and rotation motion in a body. |
(d) | mechanical advantage greater than one means that small effort can be used to lift a large load. |
1. | (a) and (b) | 2. | (b) and (c) |
3. | (c) and (d) | 4. | (b) and (d) |
A gas that can readily decolorize an acidified KMnO4 solution is:
1.
2.
3.
4.
The mechanism of a hypothetical reaction
X2 + Y2 → 2XY is given below:
(i) X2 → X + X (Fast)
(ii) X + Y2 ⇄ XY + Y (slow)
(iii) X + Y → XY (Fast)
The overall order of the reaction will be:
1. 2
2. 0
3. 1.5
4. 1
The element Z = 114 has been discovered recently. Family/group and electronic configuration from which it will belong are:
1. Carbon family and [Rn] 5f14 6d10 7s2 7p2
2. Oxygen family and [Rn] 5f14 6d10 7s2 7p4
3. Nitrogen family and [Rn] 5f14 6d10 7s2 7p6
4. Halogen family and [Rn] 5f14 6d10 7s2 7p5
The heating of phenylmethyl ether with HI produces-
1. Iodobenzene
2. Phenol
3. Benzene
4. Ethyl chloride
The correct order of acidity among the following is:
1. | \(\mathrm{CH \equiv CH > CH_3 - C \equiv CH }\) \(\mathrm{ > CH_2 = CH_2 > CH_3 - CH_3}\) |
2. | \(\mathrm{CH \equiv CH > CH_2 = CH_2 }\) \(\mathrm{ > CH_3 - C \equiv CH > CH_3 - CH_3}\) |
3. | \(\mathrm{CH_3 - CH_3 > CH_2 = CH_2 }\) \(\mathrm{ > CH_3 - C \equiv CH > CH \equiv CH }\) |
4. | \(\mathrm{ CH_2 = CH_2 > CH_3 - CH_3 }\) \(\mathrm{ > CH_3 - C \equiv CH > CH \equiv CH}\) |
The equilibrium of three reactions with their respective equilibrium constants are given below,
\( \begin{array}{lc} \mathrm{N}_2+3 \mathrm{H}_2 \rightleftharpoons 2 \mathrm{NH}_3 & \mathrm{~K}_1 \\ \mathrm{~N}_2+\mathrm{O}_2 \rightleftharpoons 2 \mathrm{NO} & \mathrm{K}_2 \\ \mathrm{H}_2+\frac{1}{2} \mathrm{O}_2 \rightleftharpoons \mathrm{H}_2 \mathrm{O} & \mathrm{K}_3 \end{array} \)
The equilibrium constant (K) of the following reaction will be :
1. \( \frac{K_{2}K_{3}^{3}}{K_{1}}\)
2. \( \frac{K_{2}K_{3}}{K_{1}}\)
3. \( \frac{K_{2}^{3}K_{3}}{K_{1}}\)
4. \( \frac{K_{3}^{3}K_{1}}{K_{2}}\)
The most acidic compound among the following is:
1. | 2. | ||
3. | 4. |