Would magnesium react with dilute sulfuric acid why or why not

Yes, magnesium will ract with dilute sulfuric acid, becasue magnesium can be oxidized to Mg (2+) cations and combine with the ion sulfate, SO4 (2-) to form magnesium sulfate, MgSO4.

This is the chemical equation

Mg + H2SO4 ⇄ MgSO4 + H2(g)↑

This is a displacement reaction, where the magnesium metal displaces the hydrogen in the molecule of sulfuric acid and leaves as H2 gas.

M{(NH₄)₂Cr₂O₇}=2A(N)+8A(H)+2A(Cr)+7A(O)

M{(NH₄)₂Cr₂O₇}=252.065 g/mol

M(Cr)=51.996 g/mol

m{(NH₄)₂Cr₂O₇}/M{(NH₄)₂Cr₂O₇}=m(Cr)/2M(Cr)

m(Cr)=2M(Cr)m{(NH₄)₂Cr₂O₇}/M{(NH₄)₂Cr₂O₇}

m(Cr)=2*51.996*35.8/252.065=14.770 g

m(Cr)=14.770 g