Hỗn hợp X gồm 0,15 mol CO2 và 0,05 mol CO .Tỉ khối hơi của khí X so với không khí là A. 1,38 B. 1,5 C. 1,25 D. 1

2 câu trả lời

   `flower`

Đáp án: `A`

Giải thích các bước giải:

Khối lượng từng chất :

`m_{CO_2}=n_{CO_2}×M_{CO_2}=0,15×44=6,6(g)`

`m_{CO}=n_{CO}×M_{CO}=0,05×28=1,4(g)`

Tổng khối lượng :

`m_{all}=6,6+1,4=8(g)`

Khối lượng mol của hỗn hợp khí :

`M_{all}=m_{all}/n_{all}=8/(0,15+0,05)=8/(0,2)=40(g//mol)`

Tỷ khối so với không khí :

`d_{all//kk}=M_{all}/M_{kk}=40/29≈1,38`

Đáp án:

`A`

Giải thích các bước giải:

Khối lượng hỗn hợp khí `X` là:

        `m_X``=``m_{CO_2}``+``m_{CO}``=``(``0,15``.``44``)``+``(``0,05``.``28``)``=``8` `(g)`

Số mol của hỗn hợp khí `X` là:

        `n_X``=``n_{CO_2}``+``n_{CO}``=``0,15``+``0,05``=``0,2` `(mol)`

Khối lượng mol của khí `X` là:

        `m_X``=``\frac{m}{n}``=``\frac{8}{0,2}``=``40` `(g``/``mol)`

Tỉ khối hơi của khí `X` so với không khí là:

        `dX``/``kk``=``\frac{M_X}{29}``=``\frac{40}{29}``≈``1,38`

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