Answer: Mg is the excess reactant for the forward reaction.
Explanation: It is a stoichiometry problem and solved with the help of given grams and using balanced equation. Grams of both the reactants are converted to moles and divided by their coefficients. The excess reactant is the one for which we get the highest number on doing above steps.
The balanced equation is:

Molar mass of silicon tetra chloride is 169.9 gram per mol and the molar mass of Mg is 24.3 gram per mol.

= 

= 2.67 mol Mg
From balanced equation, the coefficient of silicon tetra chloride is 1 and that of Mg is 2. So, we will divide the moles of silicon tetra chloride by 1 and that of Mg by 2 and see which one gives highest number.
For silicon tetra chloride,
= 0.317
and for Mg,
= 1.34
The highest number is for Mg and so the excess reactant for the forward reaction is Mg.
First you find out how much each element has
Fe=1 * 2 Fe=1
Cl=2 *3 Cl=3 *2
now we multiply each so we can balance each side.
So now we get our balanced equation
2 Fe + 3 Cl2 = 2 FeCl<span>3</span>
The number is written in scientific notation.
The significant figures are the numbers known precisely plus 1 digit that is uncertain.
When the numbers are expressed in scientific notation all the digits before 10^n are significant.
So, 7 and 8 are significant figures and the answer is that the number of significant figures is 2.
Answer: 2
Answer:
I think it’s D
Explanation:
Chemical strength, Chemical compounds have energy contained in their bonds. Chemical energy may be emitted in the form of heat during a chemical reaction, which is known as an exothermic reaction. The body transforms the chemical energy in food into mechanical energy and heat.
B.. it is a combination reaction... A + B--> AB