Answer:
The Answer is (C)
Explanation:
Reasons are when anything cools or condenses it tends to be more solid, and solids don't move.
To determine the empirical formula for the compound that contains <span>0.979 g Na, 1.365 g S, and 1.021 g O, we convert these to mole units. The molar masses to be used are:
Molar mass of Na = 23 g/mol
</span>Molar mass of S = 32 g/mol
Molar mass of O = 16 g/ mol
The number of moles is obtained using the molar mass for each element.
moles Na = 0.979 g Na/ 23 g/mol Na = 0.04256
moles S = 1.365 g Na/ 32 g/mol Na = 0.04265
moles O = 1.021 g O/ 16 g/mol Na = 0.06326
We then divide each with the smallest number of moles obtained.
Na: 0.04256/ 0.04256 = 1
S: 0.04265/ 0.04256 = 1.002 ≈ 1
O: 0.06326/ 0.04256 = 1.49 ≈ 1.5
We then have an empirical formula of NaSO₁.₅. However, chemical formulas must have only integers as subscripts, thus, we multiply each to 2. The empirical formula is then Na₂S₂O₃ also known as sodium thiosulfate.
Answer: Baking soda
Explanation:
Sodium bicarbonate has a chemical formula of NaHCO3, it is a white precipitate formed when excess carbon dioxide is bubbled through a concentrated solution of sodium hydroxide.
It is used in cooking and serves as baking powder.
Answer:
C rusting iron
Explanation:
water evaporating and melting is an example of physical change it doesn't change the H2O composition of the atoms, rubbing water on paper doesn't change any atoms or molecules. so the only answer that leaves is rusting iron because when an iron nail comes into contact with water and is then exposed to the air, it rusts, forming a brown-red substance. This process changes the chemical composition of the original substance.
