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.
C is your answer. Because if you add two of them together you get a compound.
The way a lack of water could affect cell functions is that cell membranes would lack structure.
Osmosis causes water to flow from the cell into the surrounding liquid. This causes the protoplasm all the material inside the cell, to shrink from the cell wall. Excessive water loss leading to cell wall breakdown can lead to cell death. Water is an important part of the protoplasm of living cells as it is directly involved in myriad biochemical reactions such as photosynthesis and respiration.
Without them, cells cannot move waste and byproducts absorb nutrients, carry out intracellular transport functions or send signals. Regulates body temperature. Moisten eye nose and mouth tissues. Protects body organs and tissues. Carry nutrients and oxygen to cells. Plasmolysis is a situation in which cells lose water in hypertonic solutions. the plant cells lose water causing them to shrink or shrink removing the cell cytoplasm from the cell wall.
Learn more about Cell functions here:-brainly.com/question/13880600
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