Applying the rules of significant figures, which of the following would be the correct value for the density of a substance which has a mass if 32.40 g and a volume of 2.0mL? 16.20 g/mL
16 g/mL
0.06 g/mL
5.00 g/mL

16 g/ml

Given

mass = 32.40 g

volume = 2.0mL

Required

Density

Solution

Density is a quantity derived from the mass and volume  

Density is the ratio of mass per unit volume  

Density formula:  

ρ = density  

m = mass  

v = volume  

Input the value :

ρ = 32.40 g / 2.0 ml

ρ = 16.2 g/ml

Rules for division: The least number of significant figures in the problem determines the number of significant figures in the answer.

32.40 = 4 sig.fig

2.0 = 2 sig fig

The answer must be 2 sig fig

So the answer = 16 g/ml

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explanation:

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.