During an experiment a thermometer was placed in a beaker containing hydrogen peroxide. the following observations were recorded when yeast granules were added to hydrogen peroxide. observation 1: fizzing and bubbling took place. observation 2: the temperature began to rise. based on the observation, justify the type of change (physical or chemical) that took place.

chemical change

Explanation:

A physical change is defined as a change in which a change in shape, size takes place. No new substance gets formed in these reactions. Example: Melting of ice to liquid water

A chemical change is defined as a change in which there is redistribution of atoms and chemical composition. A new substance is formed in these reactions.

Example: Oxidation of magnesium leads to formation of white magnesium oxide

When yeast is added to hydrogen peroxide, hydrogen peroxide is decomposed into oxygen and water which is a chemical reaction.

Thus as the oxygen gas is released, it leads to bubbles and the heat is released in the reaction , thus the temperature is increased.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

it should be all of them because it asks if you included all of those in your answer

explanation: