Answer:
Explanation:
A pure substance is made up solely of that substance and can't be separated into any other substances. A mixture can be separated into two or more pure substances
Answer:
N=+2
O=-2
Explanation:
The compound NO is electrically neutral.
Lets assign the oxidation number of nitrogen to be N. The oxidation number of oxygen (-2) is then used as a reference.
For the compound to have a zero charge, sum of the oxidation numbers equals zero.
N+ (-2)=0
N=+2
O=-2
Answer:

Explanation:
<u>Convert Atoms to Moles</u>
The first step is to convert atoms to moles. 1 mole of every substance has the same number of particles: 6.022 ×10²³ or Avogadro's Number. The type of particle can be different, in this case it is atoms of silver. Let's create a ratio using this information.

We are trying to find the mass of 8.23 ×10²³ silver atoms, so we multiply by that number.

Flip the ratio so the atoms of silver cancel. The ratio is equivalent, but places the other value with units "atoms Ag" in the denominator.


Condense into one fraction.


<u>Convert Moles to Grams</u>
The next step is to convert the moles to grams. This uses the molar mass, which is equivalent to the atomic mass on the Periodic Table, but the units are grams per mole.
Let's make another ratio using this information.

Multiply by the number of moles we calculated.

The moles of silver cancel out.



<u>Round</u>
The original measurement of atoms has 3 significant figures, so our answer must have the same. For the number we calculated, that is the ones place.
The 4 in the tenths place tells us to leave the 7 in the ones place.

8.23 ×10²³ silver atoms are equal to approximately <u>147 grams.</u>
The reaction between calcium carbonate and hydrochloric acid can be expressed through the chemical reaction,
CaCO3 + 2HCl --> CaCl2 + H2O + CO2
The molecular weight of calcium carbonate is 100 g/mol while that of hydrochloric acid is 36.45. The equation above depicts that 100 g of calcium carbonate can be dissolved in 72.9 g of hydrochloric acid.
x = (4 g HCl)(100 g CaCO3 / 72.9 HCl)
x = 5.49 g
Answer: 5.49 g
Answer:
Mg(NO4)2 is 180.3 g/mol
Explanation:
First find the substance formula.
Magnesium Nitrate.
Magnesium is a +2 charge.
Nitrate is a -1 charge.
So to balance the chemical formula,
We need 1 magnesium atom for every nitrate atom.
2(1) + 1(-2) = 0
So the substance formula is Mg(NO4)2.
Now find the molar mass of Mg(NO4)2.
Mg = 24.3 amu
N = 14.0 amu
O = 16.0 amu
They are three nitrogen and twelve oxygen atoms.
So you do this: 24.3 + 14.0(2) + 16.0(8) = 180.3 g/mol
So the molar is mass is 180.3 g/mol.
The final answer is Mg(NO4)2 is 180.3 g/mol
Hope it helped!