MHT CET · Chemistry · Some Basic Concepts of Chemistry
How many molecules of ammonia gas are present in \(67.2 \mathrm{dm}^3\), measured at S.T.P.?
- A \(2.0 \times 10^{24}\)
- B \(1.0 \times 10^{23}\)
- C \(1.8 \times 10^{24}\)
- D \(5.0 \times 10^{24}\)
Answer & Solution
Correct Answer
(C) \(1.8 \times 10^{24}\)
Step-by-step Solution
Detailed explanation
\(
\begin{aligned}
& \text {Number of moles of gas }=\frac{\text { Given volume }}{22.4} \\
& =\frac{67.2}{22.4}=3 \mathrm{moles}
\end{aligned}
\)
Number of molecules \(=\) moles \(\times \mathrm{N}_{\mathrm{A}}\)
\(
\begin{aligned}
& =3 \times 6 \times 10^{23} \\
& =18 \times 10^{23} \\
& =1.8 \times 10^{24}
\end{aligned}
\)
\begin{aligned}
& \text {Number of moles of gas }=\frac{\text { Given volume }}{22.4} \\
& =\frac{67.2}{22.4}=3 \mathrm{moles}
\end{aligned}
\)
Number of molecules \(=\) moles \(\times \mathrm{N}_{\mathrm{A}}\)
\(
\begin{aligned}
& =3 \times 6 \times 10^{23} \\
& =18 \times 10^{23} \\
& =1.8 \times 10^{24}
\end{aligned}
\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- Identify the concentration of the solution from following so that values of \(\Delta \mathrm{T}_{\mathrm{f}}\) and \(\mathrm{K}_{\mathrm{f}}\) are sameMHT CET 2022 Easy
- What is the hybridization of carbon atoms in fullerene?MHT CET 2017 Easy
- The IUPAC name of
MHT CET 2008 Easy - What is IUPAC name of following compound?
MHT CET 2025 Easy - Which following statement is true for vinylic halide?MHT CET 2021 Medium
- Which among the following compounds in crystalline form is used for making Nicol’s prism?MHT CET 2019 Easy
More PYQs from MHT CET
- If the shortest distance between the lines
\(\overline{\mathrm{r}}_1=\alpha \hat{i}+2 \hat{\mathrm{j}}+2 \hat{\mathrm{k}}+\lambda(\hat{i}-2 \hat{\mathrm{j}}+2 \hat{\mathrm{k}}), \lambda \in \mathbb{R}, \alpha>0 \text { and }\)
\(\overline{\mathrm{r}}_2=-4 \hat{i}-\hat{\mathrm{k}}+\mu(3 \hat{i}-2 \hat{\mathrm{j}}-2 \hat{\mathrm{k}}), \mu \in \mathrm{R}\), is 9, then the value of \(\alpha\) isMHT CET 2025 Hard - The following figures show the variation of displacement with time of a particular object.
(a)
(b)
(c)
(d)
MHT CET 2024 Medium - Calculate the ionic concentration of sparingly soluble salt BA in mol dm \({ }^{-3}\) at 300 K when equilibrium is attained if solubility product of salt is \(2.7 \times 10^{-10}\) at same temperature.MHT CET 2025 Easy
- The ventricular diastole has duration of _________ seconds.MHT CET 2020 Medium
- When a liquid flows through a tube, the Reynold's number is 900 , the flow of a liquid isMHT CET 2022 Easy
- Two cards are drawn successively with replacement from a well shuffled pack of 52 cards. Then the probability distribution of number of jacks isMHT CET 2023 Medium