NSMQ 2022 past questions with answers

Answer

0.5

1. 1.Resolve vertical forces at the foot: the normal reaction N balances the weight, so N = W.
2. 2.Take moments about the foot. The horizontal reaction at the wall R_w times the vertical height L·sin45° equals the weight W times its horizontal lever arm (L/2)·cos45°, giving R_w = W/2.
3. 3.At limiting equilibrium the frictional force F at the foot equals R_w, and μ = F/N = (W/2)/W = 0.5.

Answer

$K_c=\frac{[CO][H_2{]}^3}{[C{H}_4]}$

1. 1.For a reaction $aA+bB\rightleftharpoons cC+dD$, $K_c=\frac{[C{]}^c[D{]}^d}{[A{]}^a[B{]}^b}$ (include only gases/aqueous species; omit pure liquids/solids).
2. 2.Identify stoichiometry: $\text{ce}CH4$ (1), $\text{ce}H2O$ (liquid, 1), $\text{ce}CO$ (1), $\text{ce}H2$ (3).
3. 3.Omit the pure liquid $\text{ce}H2O(l)$ from the expression.
4. 4.Substitute the remaining species to get $K_c=\frac{[CO{]}^1[H_2{]}^3}{[C{H}_4{]}^1}$, i.e. $K_c=\frac{[CO][H_2{]}^3}{[C{H}_4]}$.

Answer

log(9)

1. 1.Recall the power rule of logarithms: $c{\log }_b(a)={\log }_b(a^c)$.
2. 2.Apply this rule to $2\log 3$ to rewrite it as $\log (3^2)$.
3. 3.Evaluate the exponent: $3^2=9$, giving the simplified form $\log (9)$.

Answer

5 g

1. 1.Compute the number of half-lives n = t / t_1/2 = 22.4 h / 5.6 h = 4.
2. 2.Use N = N₀ / 2ⁿ = 80 g / 2⁴ = 80 g / 16.
3. 3.Simplify to get N = 5 g.

Answer

(-3, 2)

1. 1.Reverse the reflection in the origin by applying $R_{\text{origin}}$ to the final point $(-2,3)$, giving $(2,-3)$.
2. 2.Reverse the reflection in the line $y=x$ by applying $R_{y=x}$ to $(2,-3)$, which swaps coordinates to $(-3,2)$.
3. 3.Conclude that the original point $A$ is $(-3,2)$.

Answer

3,3‑diethylpentane

1. 1.Identify the molecular formula $C_9{H}_{20}$ and recall alkane isomers share this formula.
2. 2.To minimize the number of substituents, choose the shortest possible parent chain (pentane) and use larger substituents (ethyl groups) instead of multiple methyls.
3. 3.Place two ethyl groups on the middle carbon of pentane to maximize symmetry and numbering priority, giving substituents at carbon-3, yielding 3,3-diethylpentane.

Answer

False

Because the ratio between consecutive terms varies (1/4, 16/9, …) instead of staying constant, the series is not geometric (exponential).

Answer

True

By definition, electric field lines start on positive charges and point in the direction a positive test charge would move, so they radiate outward from a positive point charge.

Answer

Spectator ion

Answer

Ground state