Author Topic: 2015 Chemistry Past Paper question (Read 900 times) Tweet Share

melonsinwater · « **on:** October 07, 2018, 07:23:26 pm »

http://puu.sh/BH2an/d6838c82eb.png
https://puu.sh/BH28Q/c9193f0207.png

How do you find the answer to these questions? (q19 and 20)

Please answer in detail. Thank you.

clovvy · « **Reply #1 on:** October 07, 2018, 08:20:28 pm »

Quote from: melonsinwater on October 07, 2018, 07:23:26 pm

http://puu.sh/BH2an/d6838c82eb.png
https://puu.sh/BH28Q/c9193f0207.png

How do you find the answer to these questions? (q19 or 20)

Please answer in detail. Thank you.

Hi, so these are my solutions to these questions:
Q19
$n(PbCl_2)=\frac{0.13}{278.1}=4.67\times10^{-4}molL^{-1}\\n(Pb^{2+})=4.67\times10^{-4}molL^{-1}\\c(Pb6{2+}=\frac{4.67\times10^{-4}}{0.05}=9.3\times10^{-3}molL^{-1}\, \therefore C$
Q20
$m=\frac{\Delta\,H}{C\,\Delta T}=\frac{4638\times10^3}{(4.18\times10^3)\times25}\\=4.38Jper116.2gheptan-1-ol\\\frac{44.38}{116.2}=0.38kg\, \therefore D$

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Author Topic: 2015 Chemistry Past Paper question (Read 900 times) Tweet Share

melonsinwater

2015 Chemistry Past Paper question

clovvy

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