Answer: 3.5 moles
Explanation:
Based on Avogadro's law:
1 mole of any substance has 6.02 x 10^23 molecules
So, 1 mole of SiO4 = 6.02 x 10^23 molecules
Zmoles of SiO4 = 2.1 x 10^{24} molecules
To get the value of Z, cross multiply:
(2.1 x 10^{24} molecules x 1mole) = (6.02 x 10^23 molecules x Z moles)
2.1 x 10^{24} molecules = (6.02 x 10^23 x Z)
Z = (2.1 x 10^{24}) ➗ (6.02 x 10^23)
Z = 3.5 moles
Thus, there are 3.5 moles of SiO4.
Answer:
A
Explanation:
A linear correlation means the increase in one variable cause an increase in the other variable. In a graph, the linear correlation can be demonstrated by a right-slanted straight diagonal line. Therefore if an increase in carbon dioxide causes a directly proportional increase in global temperatures then the two are correlated.
K has the lowest and Br has the higher
Hello!
The initial mass of
Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O) is 23,08 g
The chemical reaction for the dehydrating of
Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O) is the following:
MgSO₄·7H₂O(s) + Δ → MgSO₄(s) + 7H₂O(g)
We know that the sample loses 11,80 g upon heating.
That mass is the mass of Water that is released as vapor. Knowing that piece of information, we can apply the following conversion factor to go from the mass of water to the moles of water and back to the mass of the original compound (mi).

Have a nice day!
Answer:
We could do two 1:50 dilutions and one 1:4 dilutions.
Explanation:
Hi there!
A solution that is 1000 ug/ ml (or 1000 mg / l) is 1000 ppm.
Knowing that 1 ppm = 1000 ppb, 100 ppb is 0.1 ppm.
Then, we have to dilute the stock solution (1000 ppm / 0.1 ppm) 10000 times.
We could do two 1:50 dilutions and one 1:4 dilutions (50 · 50 · 4 = 10000). Since the first dilution is 1:50, you will use the smallest quantity of the stock solution (if we use the 10.00 ml flask):
First step (1:50 dilution):
Take 0.2 ml of the stock solution using the third dispenser (20 - 200 ul), and pour it in the 10.00 ml flask. Fill with water to the mark (concentration : 1000 ppm / 50 = 20 ppm).
Step 2 (1:50 dilution):
Take 0.2 ml of the solution made in step 1 and pour it in another 10.00 ml flask. Fill with water to the mark. Concentration 20 ppm/ 50 = 0.4 ppm)
Step 3 (1:4 dilution):
Take 2.5 ml of the solution made in step 3 (using the first dispenser 1 - 5 ml) and pour it in a 10.00 ml flask. Fill with water to the mark. Concentration 0.4 ppm / 4 = 0.1 ppm = 100 ppb.