sửa câu 58. It;s isn't necessary to book tickets...document

56. Please inform the relevant authorities without delay.

57. After the computer had crashed, I saved my document.

58. You don't necessary to book tickets for the show in advance.

                                        Na₂O + H₂O → 2NaOH

                                           1            1            2

                                          0,1                       0,2

a).  n_Na2O=\(\dfrac{6,2}{62}\)= 0,1(mol)

       C_M=\(\dfrac{n}{V}\)=\(\dfrac{0,1}{4}\)= 0,025M

b).              Na₂O + H₂SO₄ → Na₂SO₄ + H₂O

                      1            1                1            1

                     0,1        0,1

m_H2SO4= n.M = 0,1 . 98 = 9,8g

⇒m_ddH2SO4= m_ct=\(\dfrac{mct.100\%}{C\%}\)= \(\dfrac{9,8.100}{20}\)= 49(g).

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John asked if I was doing my homewwork then,Mary

thi thì tự làm bạn nhé!

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