question 1 (1 point)
saved
in the first reaction with epsom salt added to ammonia, what evidence was there for a chemical reaction taking place?

question 1 options:

color change

formation of a precipitate

increase in temperature

formation of bubbles

question 2 (1 point)
in the second reaction with iron and oxygen, what evidence for a chemical reaction was not observed?

question 2 options:

new substance formed

formation of a precipitate

color change

change in temperature

question 3 (1 point)
in the third reaction which gas is released when baking soda is added to vinegar?

question 3 options:

carbon dioxide

hydrogen gas

water

oxygen

question 4 (1 point)
in the fourth reaction with copper sulfate and sodium hydroxide, what is the precipitate that is formed?

question 4 options:

cu(oh)2

naoh

cuso4

na2so4

Question #1) The formation of a precipitate

Question # 2) ? Insufficient information

Question # 3) when you mix baking soda (sodium bicarbonate) with vinegar (acetic acid) the baking soda is the base and the vinegar is the acid, the baking soda takes a proton from the acid and the products of the reaction are H2O and CO2. The initial two products are carbonic acid and sodium acetate and the second part of the reaction is the decomposition reaction with the carbonic acid immediately decomposing into water and carbon dioxide gas. The CO2 rises to the surface creating bubbles.

Question #4) when sodium hydroxide, a strong base reacts with copper sulfate an acidic salt as a blue precipitate of copper hydroxide is produced with ions of sodium sulfate in solution. This represents a double displacement reaction as well as a precipitation reaction.

Explanation:

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3