Start with the equation of the reaction at 115 ° C
Sn+2Cl2 = SnCl4
Thus 1 mole of Sn combined with 2 moles of chlorine produces 1 mole of SnCl4.
By proportion,
1.425 moles of Sn will combine with 2.85 moles of chlorine to produce 1.425 moles of stannous chloride.
You may round 1.425 to 3 significant figures.
