You mix solution a with solution b in a beaker. which of the following observations does not you prove that a chemical reaction has occurred?
a the beaker becomes warm.
b you see gas bubble out of solution.
c solution a, solution b, and the mixture are all yellow.
d none of the above; all prove that a chemical reaction has occurred.
in the reaction described by the word equation sodium + water sodium hydroxide + hydrogen gas
a sodium hydroxide is a product.
b sodium is a product.
c both (a) and (c)
d water is a reactant.

Part 1: A and B; Part 2: A and D

Explanation:

Part 1. Evidence of reaction

The evolution of heat and/or bubbles of gas are evidence that a reaction has occurred.

C is wrong. If adding yellow Solution A to yellow Solution B gives a yellow mixture, that is not evidence of reaction. You need a colour change to provide evidence.

Part 2. Identifying reactants and products

Reactants are on the left side of the reaction arrow, and products are on the right.

Thus, water is a reactant, and sodium hydroxide is a product.

B is wrong. Sodium is a reactant.

1) Solution A, solution B, and the mixture are all yellow.

2) sodium hydroxide is a product

water is a reactant.

Explanation:

In a chemical reaction mixture , change in colour, change in temperature of reaction mixture or evolution of gas all confirm that a chemical reaction has taken place. If the colour of the reaction mixture remains the same overtime, it may be an indication that a chemical reaction did not take place in the mixture.

Looking at the reaction equation:

sodium + water> sodium hydroxide + hydrogen gas

Species on the lefthand side of any chemical reaction equation are called reactants while the species on the right hand side of the reaction equation are called products . hence sodium hydroxide is a product while water is a reactant.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.