Each element or compound has a molar mass, which is calculated by multiplying the atomic mass of each element by the amount of atoms of that element, and summing the results of each element. The molar mass is measured in g/mol. So you divide the mass in grams by the molar mass to get the amount of moles.
Example:
There are 5g of water.
Calculate the amount of moles.
The water's formula is H2O, so the molar mass of it is
g/mol.
The amount of moles is:
5g ÷ 18g/mol ~ 0.28mol
Answer:
the moluculer formula is the answer
Explanation:
corrected question: A chemist adds 135mL of a 0.21M zinc nitrate solution to a reaction flask. Calculate the mass in grams of zinc nitrate the chemist has added to the flask. Round your answer to significant digits.
Answer:
5.37g
Explanation:
0.21M means ; 0.21mol/dm³
1dm³=1L , so we can say 0.21mol/L
if 0.21mol of Zinc nitrate is contained in 1L of water
x will be contained in 135mL of water
x= 0.21*135*10³/1
=0.02835moles
number of moles= mass/ molar mass
mass= number of moles *molar mas
molar mass of Zn(NO₃)₂=189.36 g/mol
mass= 0.02835 *189.36
mass=5.37g
An aqueous solution contains the following ions Cl⁻, Ag⁺, Pb²⁺, NO₃⁻ & SO₄²⁻ and more than one precipitate will form are AgCl, PbCl₂, PbSO₄ & Ag₂SO₄.
<h3>What is precipitate?</h3>
Precipitate is the insoluble compound which is present at the bottom of any chemical reaction in the solid state.
If in an aqueous solution Cl⁻, Ag⁺, Pb²⁺, NO₃⁻ & SO₄²⁻ ions are present then:
- Compounds AgCl, PbCl₂, PbSO₄ & Ag₂SO₄ are not soluble in water as it is present in the form of precipitate.
- Pb(NO₃)₂ is fully soluble in water and will not make precipitate.
Hence precipitates are AgCl, PbCl₂, PbSO₄ & Ag₂SO₄.
To know more about precipitates, visit the below link:
brainly.com/question/2437408
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Answer:
343.98 nm is the longest wavelength of radiation with enough energy to break carbon–carbon bonds.
Explanation:
A typical carbon–carbon bond requires 348 kJ/mol=348000 J/mol
Energy required to breakl sigle C-C bond:E
where,
E = energy of photon
h = Planck's constant = 
c = speed of light = 
= wavelength of the radiation
Now put all the given values in the above formula, we get the energy of the photons.
343.98 nm is the longest wavelength of radiation with enough energy to break carbon–carbon bonds.
