(来学网)50gNaNO2溶于水并稀释至250ml,则此溶液的质量浓度是
  • A.
    (来学网)50g/l
  • B.
    (来学网)100g/L
  • C.
    (来学网)200g/L
  • D.
    (来学网)250g/
  • E.
    (来学网)25g/l