现要配制\(\rm{1mol/LNa_{2}CO_{3}}\)溶液\(\rm{250}\) \(\rm{mL}\),求:
\(\rm{(1)}\)需要固体\(\rm{Na_{2}CO_{3}}\) ______ \(\rm{g}\);
\(\rm{(2)}\)需要含结晶水的碳酸钠晶体\(\rm{(Na_{2}CO_{3}⋅10H_{2}O)}\) ______ \(\rm{g}\);
\(\rm{(3)}\)需要物质的量浓度为\(\rm{4}\) \(\rm{mol/L}\)的\(\rm{Na_{2}CO_{3}}\)溶液 ______ \(\rm{mL}\);
\(\rm{(4)}\)需要溶质的质量分数为\(\rm{12\%}\)、密度为\(\rm{1.12}\) \(\rm{g/cm^{3}}\)的\(\rm{Na_{2}CO_{3}}\)溶液 ______ \(\rm{mL}\).