Answer:
density equals weigt divided by volume
Explanation:

Hard water contains certain minerals that can be rougher on the skin and hair.
Overfishing is an example of human impact on biodiversity.
In simple terms, overfishing means that the sea animals hunted for food ( fishes, crustaceans, mollusks etc.) in a year are hunted in numbers greater than the number of newborn individuals of that species in that year. This means that the populations of these animals do not have the time to regrow their numbers.
This results in a dramatic decline of populations of many marine animals.
Answer:- 324.3 grams.
Solution:- We have been given with 6.0 moles of nitrous acid and asked to calculate it's grams. Moles to grams is a unit conversion and for doing this conversion we multiply the given moles by the molar mass of the compound.
Molar mass is the formula mass and to calculate this the atomic masses of each atom are multiplied by their respective subscripts that is the number of the atom in the compound .
For example,
has one nitrogen atom and one oxygen atom. So, the molar mass of this is = atomic mass of N + 2(atomic mass of O)
= 14 + 2(16)
= 14 + 32
= 46 gram per mol
gram per mol is the unit of molar mass. So, the molar mass of
is 46 grams per mol.
Let's calculate the molar mass of nitrous acid using the same concept.
molar mass of [
= 1 + 14 + 2(16)
= 1 + 14 + 32
= 47 grams per mol
Now, 6.9 moles of nitrous acid could easily be converted to grams as:

= 324.3 g
Hence, the mass of 6.9 moles of nitrous acid is 324.3 grams.
Answer:
This question lacks options, the options are:
A. 2.89 x 1022
B. 8.66 x 1022
C. 3.66 x 1023
D. 1.10 x 1024
E. 3.29 x 1024
The answer is C. 3.66 × 10^23
Explanation:
In the chemical compound given as follows: Co2(HPO4)3, hydrogenphosphate ion is (HPO4)3.
Number of moles of hydrogenphosphate ion can be calculated using the formula
mole (n) = mass (m) /molar mass (MM)
Molar mass of (HPO4)3;
{1 + 31 + 16(4)}3
= {32 + 64)3
= (96)3
= 288g/mol
mole = 175/288
mole = 0.6076
mole = 0.607mol
The formula of units of hydrogenphosphate ion can be calculated by multiplying number of moles by Avogadro's number (6.022 × 10²³)
6.022 × 10²³ × 0.607
= 3.655 × 10²³
= 3.66 × 10²³