(b) Magnesium reacts very slowly with cold water but it reacts faster with steam, H,0,
and forms magnesium oxide, MgO, and hydrogen.
Write the balanced equation for the reaction between magnesium and steam.
(2)
(C) The electronic configurations of magnesium and calcium are
magnesium 2.8.2
calcium 2.8.8.2
When magnesium and calcium react with water they form positive ions.
Suggest an explanation, in terms of their electronic configurations, why calcium is
more reactive than magnesium.
(2)

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

i'm assuming that it's c.) red bank..

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml