306694
\(\mathrm{10^{21}}\) molecules are removed from \(\mathrm{200 \mathrm{mg}}\) of \(\mathrm{\mathrm{CO}_{2}}\). The moles of \(\mathrm{\mathrm{CO}_{2}}\) left are
1 \(\mathrm{2.88 \times 10^{-3}}\)
2 \(\mathrm{28.8 \times 10^{-3}}\)
3 \(\mathrm{288 \times 10^{-3}}\)
4 \(\mathrm{28.8 \times 10^{3}}\)
Explanation:
1 mole of \(\mathrm{\mathrm{CO}_{2}}\) molecule \(\mathrm{=6.023 \times 10^{23}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=44 \mathrm{~g}}\) of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{\therefore 10^{21}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=\dfrac{44}{6.023 \times 10^{23}} \times 10^{21} \mathrm{gCO}_{2}}\) \(\mathrm{=7.31 \times 10^{-2} \mathrm{~g}=73.1 \mathrm{mg}}\) \(\mathrm{\therefore \mathrm{CO}_{2}}\) left \(\mathrm{=200-73.1=126.9 \mathrm{mg}}\) \(\mathrm{=126.9 \times 10^{-3} \mathrm{~g}}\) Hence, moles of \(\mathrm{\mathrm{CO}_{2}}\) left \(\mathrm{=\dfrac{\text { given mass }}{\text { molar mass }}}\) \(\mathrm{=\dfrac{126.9 \times 10^{-3} \mathrm{~g}}{44 \mathrm{~g} / \mathrm{mol}}}\) \(\mathrm{=2.88 \times 10^{-3} \mathrm{~mol}}\)
AIIMS - 2012
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306695
One atom of an element weighs \(1.8 \times 10^{-22} \mathrm{~g}\). Its atomic mass is
1 29.9
2 154
3 108.36
4 18
Explanation:
Mass of 1 atom of an element \( = 1.8 \times {10^{ - 22}}\;{\rm{g}}\) Mass of \(6.023 \times {10^{23}}\) atoms of an element \( = 6.023 \times {10^{23}} \times 1.8 \times {10^{ - 22}}\;{\rm{g}}\) \( = 6.023 \times 1.8 \times 10\;{\rm{g}} = 108.36\;{\rm{g}}\) Hence, atomic mass of element\( = 108.36\;{\rm{g}}\)
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306696
What is the mass of \(\mathrm{33.6 \mathrm{dm}^{3}}\) of methane gas at S.T.P.?
1 \(\mathrm{4.8 \times 10^{-2} \mathrm{~kg}}\)
2 \(\mathrm{3.3 \times 10^{-2} \mathrm{~kg}}\)
3 \(\mathrm{1.6 \times 10^{-2} \mathrm{~kg}}\)
4 \(\mathrm{2.4 \times 10^{-2} \mathrm{~kg}}\)
Explanation:
No.of moles \(\mathrm{=\dfrac{\text { Volume }\left(\mathrm{dm}^{3}\right) \text { at STP }}{22.4}}\) \(\mathrm{=\dfrac{33.6}{22.4}=1.5 \mathrm{moles}}\) Mass \(\mathrm{(}\) in gram \(\mathrm{)=}\) No. of moles \(\mathrm{\times}\) gram molar mass \(\mathrm{=1.5 \times 16=24 \mathrm{~g}}\) \(\mathrm{=2.4 \times 10^{-2} \mathrm{~kg}}\)
306694
\(\mathrm{10^{21}}\) molecules are removed from \(\mathrm{200 \mathrm{mg}}\) of \(\mathrm{\mathrm{CO}_{2}}\). The moles of \(\mathrm{\mathrm{CO}_{2}}\) left are
1 \(\mathrm{2.88 \times 10^{-3}}\)
2 \(\mathrm{28.8 \times 10^{-3}}\)
3 \(\mathrm{288 \times 10^{-3}}\)
4 \(\mathrm{28.8 \times 10^{3}}\)
Explanation:
1 mole of \(\mathrm{\mathrm{CO}_{2}}\) molecule \(\mathrm{=6.023 \times 10^{23}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=44 \mathrm{~g}}\) of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{\therefore 10^{21}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=\dfrac{44}{6.023 \times 10^{23}} \times 10^{21} \mathrm{gCO}_{2}}\) \(\mathrm{=7.31 \times 10^{-2} \mathrm{~g}=73.1 \mathrm{mg}}\) \(\mathrm{\therefore \mathrm{CO}_{2}}\) left \(\mathrm{=200-73.1=126.9 \mathrm{mg}}\) \(\mathrm{=126.9 \times 10^{-3} \mathrm{~g}}\) Hence, moles of \(\mathrm{\mathrm{CO}_{2}}\) left \(\mathrm{=\dfrac{\text { given mass }}{\text { molar mass }}}\) \(\mathrm{=\dfrac{126.9 \times 10^{-3} \mathrm{~g}}{44 \mathrm{~g} / \mathrm{mol}}}\) \(\mathrm{=2.88 \times 10^{-3} \mathrm{~mol}}\)
AIIMS - 2012
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306695
One atom of an element weighs \(1.8 \times 10^{-22} \mathrm{~g}\). Its atomic mass is
1 29.9
2 154
3 108.36
4 18
Explanation:
Mass of 1 atom of an element \( = 1.8 \times {10^{ - 22}}\;{\rm{g}}\) Mass of \(6.023 \times {10^{23}}\) atoms of an element \( = 6.023 \times {10^{23}} \times 1.8 \times {10^{ - 22}}\;{\rm{g}}\) \( = 6.023 \times 1.8 \times 10\;{\rm{g}} = 108.36\;{\rm{g}}\) Hence, atomic mass of element\( = 108.36\;{\rm{g}}\)
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306696
What is the mass of \(\mathrm{33.6 \mathrm{dm}^{3}}\) of methane gas at S.T.P.?
1 \(\mathrm{4.8 \times 10^{-2} \mathrm{~kg}}\)
2 \(\mathrm{3.3 \times 10^{-2} \mathrm{~kg}}\)
3 \(\mathrm{1.6 \times 10^{-2} \mathrm{~kg}}\)
4 \(\mathrm{2.4 \times 10^{-2} \mathrm{~kg}}\)
Explanation:
No.of moles \(\mathrm{=\dfrac{\text { Volume }\left(\mathrm{dm}^{3}\right) \text { at STP }}{22.4}}\) \(\mathrm{=\dfrac{33.6}{22.4}=1.5 \mathrm{moles}}\) Mass \(\mathrm{(}\) in gram \(\mathrm{)=}\) No. of moles \(\mathrm{\times}\) gram molar mass \(\mathrm{=1.5 \times 16=24 \mathrm{~g}}\) \(\mathrm{=2.4 \times 10^{-2} \mathrm{~kg}}\)
306694
\(\mathrm{10^{21}}\) molecules are removed from \(\mathrm{200 \mathrm{mg}}\) of \(\mathrm{\mathrm{CO}_{2}}\). The moles of \(\mathrm{\mathrm{CO}_{2}}\) left are
1 \(\mathrm{2.88 \times 10^{-3}}\)
2 \(\mathrm{28.8 \times 10^{-3}}\)
3 \(\mathrm{288 \times 10^{-3}}\)
4 \(\mathrm{28.8 \times 10^{3}}\)
Explanation:
1 mole of \(\mathrm{\mathrm{CO}_{2}}\) molecule \(\mathrm{=6.023 \times 10^{23}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=44 \mathrm{~g}}\) of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{\therefore 10^{21}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=\dfrac{44}{6.023 \times 10^{23}} \times 10^{21} \mathrm{gCO}_{2}}\) \(\mathrm{=7.31 \times 10^{-2} \mathrm{~g}=73.1 \mathrm{mg}}\) \(\mathrm{\therefore \mathrm{CO}_{2}}\) left \(\mathrm{=200-73.1=126.9 \mathrm{mg}}\) \(\mathrm{=126.9 \times 10^{-3} \mathrm{~g}}\) Hence, moles of \(\mathrm{\mathrm{CO}_{2}}\) left \(\mathrm{=\dfrac{\text { given mass }}{\text { molar mass }}}\) \(\mathrm{=\dfrac{126.9 \times 10^{-3} \mathrm{~g}}{44 \mathrm{~g} / \mathrm{mol}}}\) \(\mathrm{=2.88 \times 10^{-3} \mathrm{~mol}}\)
AIIMS - 2012
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306695
One atom of an element weighs \(1.8 \times 10^{-22} \mathrm{~g}\). Its atomic mass is
1 29.9
2 154
3 108.36
4 18
Explanation:
Mass of 1 atom of an element \( = 1.8 \times {10^{ - 22}}\;{\rm{g}}\) Mass of \(6.023 \times {10^{23}}\) atoms of an element \( = 6.023 \times {10^{23}} \times 1.8 \times {10^{ - 22}}\;{\rm{g}}\) \( = 6.023 \times 1.8 \times 10\;{\rm{g}} = 108.36\;{\rm{g}}\) Hence, atomic mass of element\( = 108.36\;{\rm{g}}\)
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306696
What is the mass of \(\mathrm{33.6 \mathrm{dm}^{3}}\) of methane gas at S.T.P.?
1 \(\mathrm{4.8 \times 10^{-2} \mathrm{~kg}}\)
2 \(\mathrm{3.3 \times 10^{-2} \mathrm{~kg}}\)
3 \(\mathrm{1.6 \times 10^{-2} \mathrm{~kg}}\)
4 \(\mathrm{2.4 \times 10^{-2} \mathrm{~kg}}\)
Explanation:
No.of moles \(\mathrm{=\dfrac{\text { Volume }\left(\mathrm{dm}^{3}\right) \text { at STP }}{22.4}}\) \(\mathrm{=\dfrac{33.6}{22.4}=1.5 \mathrm{moles}}\) Mass \(\mathrm{(}\) in gram \(\mathrm{)=}\) No. of moles \(\mathrm{\times}\) gram molar mass \(\mathrm{=1.5 \times 16=24 \mathrm{~g}}\) \(\mathrm{=2.4 \times 10^{-2} \mathrm{~kg}}\)
306694
\(\mathrm{10^{21}}\) molecules are removed from \(\mathrm{200 \mathrm{mg}}\) of \(\mathrm{\mathrm{CO}_{2}}\). The moles of \(\mathrm{\mathrm{CO}_{2}}\) left are
1 \(\mathrm{2.88 \times 10^{-3}}\)
2 \(\mathrm{28.8 \times 10^{-3}}\)
3 \(\mathrm{288 \times 10^{-3}}\)
4 \(\mathrm{28.8 \times 10^{3}}\)
Explanation:
1 mole of \(\mathrm{\mathrm{CO}_{2}}\) molecule \(\mathrm{=6.023 \times 10^{23}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=44 \mathrm{~g}}\) of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{\therefore 10^{21}}\) molecules of \(\mathrm{\mathrm{CO}_{2}}\) \(\mathrm{=\dfrac{44}{6.023 \times 10^{23}} \times 10^{21} \mathrm{gCO}_{2}}\) \(\mathrm{=7.31 \times 10^{-2} \mathrm{~g}=73.1 \mathrm{mg}}\) \(\mathrm{\therefore \mathrm{CO}_{2}}\) left \(\mathrm{=200-73.1=126.9 \mathrm{mg}}\) \(\mathrm{=126.9 \times 10^{-3} \mathrm{~g}}\) Hence, moles of \(\mathrm{\mathrm{CO}_{2}}\) left \(\mathrm{=\dfrac{\text { given mass }}{\text { molar mass }}}\) \(\mathrm{=\dfrac{126.9 \times 10^{-3} \mathrm{~g}}{44 \mathrm{~g} / \mathrm{mol}}}\) \(\mathrm{=2.88 \times 10^{-3} \mathrm{~mol}}\)
AIIMS - 2012
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306695
One atom of an element weighs \(1.8 \times 10^{-22} \mathrm{~g}\). Its atomic mass is
1 29.9
2 154
3 108.36
4 18
Explanation:
Mass of 1 atom of an element \( = 1.8 \times {10^{ - 22}}\;{\rm{g}}\) Mass of \(6.023 \times {10^{23}}\) atoms of an element \( = 6.023 \times {10^{23}} \times 1.8 \times {10^{ - 22}}\;{\rm{g}}\) \( = 6.023 \times 1.8 \times 10\;{\rm{g}} = 108.36\;{\rm{g}}\) Hence, atomic mass of element\( = 108.36\;{\rm{g}}\)
CHXI01:SOME BASIC CONCEPTS OF CHEMISTRY
306696
What is the mass of \(\mathrm{33.6 \mathrm{dm}^{3}}\) of methane gas at S.T.P.?
1 \(\mathrm{4.8 \times 10^{-2} \mathrm{~kg}}\)
2 \(\mathrm{3.3 \times 10^{-2} \mathrm{~kg}}\)
3 \(\mathrm{1.6 \times 10^{-2} \mathrm{~kg}}\)
4 \(\mathrm{2.4 \times 10^{-2} \mathrm{~kg}}\)
Explanation:
No.of moles \(\mathrm{=\dfrac{\text { Volume }\left(\mathrm{dm}^{3}\right) \text { at STP }}{22.4}}\) \(\mathrm{=\dfrac{33.6}{22.4}=1.5 \mathrm{moles}}\) Mass \(\mathrm{(}\) in gram \(\mathrm{)=}\) No. of moles \(\mathrm{\times}\) gram molar mass \(\mathrm{=1.5 \times 16=24 \mathrm{~g}}\) \(\mathrm{=2.4 \times 10^{-2} \mathrm{~kg}}\)