Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
= Avogadro's number = 
For the 4.12 g sample
Moles of a substance is given by
Number of molecules is given by
For the 19.37 g sample
Number of molecules is given by
So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
PH + pOH = 14
11.8 + pOH = 14
pOH = 14 - 11.8
pOH = 2.2
[OH-] = 10 ^- pOH
[OH-] = 10 ^- 2.2
[OH-] = <span>6.33 x 10^-3 M
</span>
Answer B
hope this helps!
Answer:
Antifreeze is whats used to keep your engine cool without freezing.
Explanation:
it keeps the engine from overheating.
It also prevents corrosion.
Here is a quote from google "Antifreeze works because the freezing and boiling points of liquids are “colligative” properties. This means they depend on the concentrations of “solutes,” or dissolved substances, in the solution. A pure solution freezes because the lower temperatures cause the molecules to slow down"
That quote is from "The Science Behind Antifreeze"
If you have any questions feel free to ask in the comments.
Explanation:
Sodium metal reacts rapidly with water to form a colourless basic solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The reaction continues even when the solution becomes basic. The resulting solution is basic because of the dissolved hydroxide.
