Respuesta :
Answer:
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
[tex]\underbrace{\hbox{sodium + water }}_{\hbox{reactants}} \longrightarrow \, \underbrace{\hbox{ sodium hydroxide + hydrogen gas}}_{\hbox{products}}[/tex]
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.
Answer:
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.