Answer: The missing coefficient is 2.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

As in the products, there are 2 atoms of sodium, thus there will be 2 atoms of of sodium in the reactant as well. This will balance the number of hydrogen and oxygen atoms as well.
Thus the missing coefficient is 2.
Answer:
The correct answer is - right-side up.
Explanation:
A diverging mirror is a curved mirror that can be bulge outside towards the source of light called a convex mirror or inward away from the source of light called a concave mirror.
A convex mirror is a mirror that forms an image bigger and but right side up or exact as the object direction also called a virtual image. It appears to be bigger than the real object and not upside down as concave mirrors.
Answer:
Explanation: I also have a question if anyone can help in chem please
You would have started with 5 grams of reactants