Chemistry

posted by .

How do you calculate the molar masses for Strontium Phosphate and Chromium(III)Nitride using significant figures correctly?

• Chemistry -

I am looking these atomic masses up at this site:
http://environmentalchemistry.com/yogi/reference/molar.html
For Sr3(PO4)2
Sr = 87.62 x 3 = 262.86
P = 30.97376 x 2 = 61.94752
O = 15.9994 x 8 = 127.9952
Total = 452.80272
The first multiplication allows 4 s.f. and I like to add one to keep from making rounding error; therefore, we will call it 262.86 (with the last place questionable).
The P has 7 s.f. so all will go.
The O has 6 s.f. so that will be 127.9952 with the 2 questionable.
Now, for adding the least precise number is .86 (two places to the right of the decimal); therefore, we can't have more than two places to the right of the decimal in the sum. That makes it 452.80 and since the 6 in .86 was carried as an "extra" I would truncate that last zero to make it 452.8

Similar Questions

1. chemistry

Find the molar mass of Chromium (III) Hydrogen Phosphate. Also, what is the chemical formula for this molecule?
2. Chemistry

Hi I just need help with question (ii) and (iii), i know how to work out (i) A solution is prepared by dissolving 0.2222 (±0.0002) g of KIO3 in 50.00 (±0.05) mL (i) Calculate the molar mass of KIO3 with its associated uncertainty …
3. chemistry

A solution is prepared by dissolving 0.2222 (¡¾0.0002) g of KIO3 in 50.00 (¡¾0.05) mL. (i) Calculate the molar mass of KIO3 with its associated uncertainty to the correct number of significant figures. (ii) Find the molarity and …
4. chemistry

If 15.0 grams of Iron (III) oxide reacts with 25.0 grams of Strontium phosphate, how many grans of Iron (III) phosphate will be produced?
5. Chemistry 101

A solution containing 83.100 g of sodium hydroxide [molar mass = 40.0 g/mol] was neutralised using phosphoric acid. Calculate the moles of sodium phosphate formed (assuming that the reaction goes to completion). Give your answer to …
6. chemistry

Use the molar mass of the following in order to calculate the number of moles from the given masses. Watch the significant figures a) 0.025 g of oxygen b)0.657 g og copper c) 0.7 g of chlorine I know how to calculate with finding the …
7. chemistry

When aqueous solutions of chromium(III) bromide and potassium phosphate are combined, solid chromium(III) phosphate and a solution of potassium bromide are formed. The net ionic equation for this reaction is:
8. chemistry

QUESTION 11 Information Set 1: Chromium (III) iodate has a Ksp at 25°C of 5.0 x 10–6. 125 mL of a solution contains 0.0050 mol L–1 Cr (III) ion. What is the molar solubility of chromium (III) iodate at 25°C?
9. Analytical Chemistry

A solution is prepared by dissolving 0.2222 (¡¾0.0002) g of KIO3 in 50.00 (¡¾0.05) mL. (i) Calculate the molar mass of KIO3 with its associated uncertainty to the correct number of significant figures. (ii) Find the molarity and …
10. Chemistry

The equilibrium concentration of phosphate ion in a saturated chromium(III) phosphate solution is

More Similar Questions