\[\eqalign{ & a]\,\,{m_{CuO}} = {n_{CuO}}.{M_{CuO}} = 0,25.80 = 20\,\,gam \cr & b]\,\,{m_{{H_2}S{O_4}}} = {n_{{H_2}S{O_4}}}.{M_{{H_2}S{O_4}}} = 0,125.98 = 12,25\,\,gam \cr & c]\,\,{n_{{H_2}}} = {{{V_{{H_2}}}} \over {22,4}} = {{4,48} \over {22,4}} = 0,2\,\,mol \cr & {m_{{H_2}}} = {n_{{H_2}}}.{M_{{H_2}}} = 0,2.2 = 0,4\,\,\,gam \cr & d]\,\,{n_{S{O_2}}} = {{{V_{S{O_2}}}} \over {22,4}} = {{15,68} \over {22,4}} = 0,7\,mol \cr & {m_{S{O_2}}} = {n_{S{O_2}}}.{M_{S{O_2}}} = 0,7.64 = 44,8\,gam \cr} \]
Đề bài
Tính khối lượng của những chất sau:
a] 0,25 mol đồng [II] oxit [CuO]
b] 0,125 mol axit sunfuric [H2SO4]
c] 4,48 l khí hiđro [đktc].
d] 15,68 l khí sunfurơ [SO2] ở đktc
Lời giải chi tiết
\[\eqalign{ & a]\,\,{m_{CuO}} = {n_{CuO}}.{M_{CuO}} = 0,25.80 = 20\,\,gam \cr & b]\,\,{m_{{H_2}S{O_4}}} = {n_{{H_2}S{O_4}}}.{M_{{H_2}S{O_4}}} = 0,125.98 = 12,25\,\,gam \cr & c]\,\,{n_{{H_2}}} = {{{V_{{H_2}}}} \over {22,4}} = {{4,48} \over {22,4}} = 0,2\,\,mol \cr & {m_{{H_2}}} = {n_{{H_2}}}.{M_{{H_2}}} = 0,2.2 = 0,4\,\,\,gam \cr & d]\,\,{n_{S{O_2}}} = {{{V_{S{O_2}}}} \over {22,4}} = {{15,68} \over {22,4}} = 0,7\,mol \cr & {m_{S{O_2}}} = {n_{S{O_2}}}.{M_{S{O_2}}} = 0,7.64 = 44,8\,gam \cr} \]