I believe the answer is 4.2
This problem requires that you know nomenclature, to identify the formula of the compond from its name, and the way how to determine the formula mass once you know formula.
1) Nomenclature: Chromate
Chromate is an ion (anion) from the chromic acid.
Chromic acid is formed from Chromic oxyde with the atomic number 6.
Then Cr + O2 -> Cr2O6 = CrO3
CrO3 + H2O -> H2CrO4
H2CrO4 = 2H(+) + CrO4 (2-) <---- this is the ion chromate
Now you have to join the chromate ion with the sodium ion => Na2 (CrO4)
2) Now you can calculate the molar mass of the formula Na2(CrO4).
You must only muliply every subscript times the atomic mass of the element:
Na2 => 2 * 23 g/mol = 46 g/mol
Cr => 52 g/mol
O4 => 4 * 16g/mol = 64 g/mol
Formula mass = 46 g/mol + 52 g/mol + 64 g/mol = 162 g/mol
I used the numbers with less significant figures thant the problem required but the answer is evident. Also, g / mol = a.m.u = atomic mass unit.
Answer: 161.97 a.m.u
A trait is like a quality and a characteristic is something that makes you different from others, it’s like a unique attribute. For exemple the sound of your laugh if you have a weird one could be a characteristic.
Answer:
The metal strip on the left has a lower activity than the one on the right.
(Took the exam)
Answer:
0.200 M
Explanation:
Step 1: Given data
- Mass of CoCl₂ (m): 2.60 g
- Molar mass of CoCl₂ (M): 130. g/mol
- Volume of solution (V): 100. mL (0.100 L)
Step 2: Calculate the moles (n) of CoCl₂ (solute)
We will use the following expression.
n = m / M
n = 2.60 g / (130. g/mol) = 0.0200 mol
Step 3: Calculate the molar concentration of the solution
Molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
M = 0.0200 mol/0.100 L = 0.200 M