chemistry questions?

Question

1)what is the mass, in grams, of a cubic meter ofblasa wood if the density of balsa wood is .02 g/mL?

2)A student measures a volume as 25 mL, whereas the correct volume is 23 mL. What is the percent error?

3)What is the volume of 700.0 g. of ether if the density of ether is .70g/mL?

4)The density of aluminum is 2.70 g/cm cubed. what is the mass of a cube of aluminum 1.oo cm on each edge?

5) A 10 cm cubed sample of an unknown liquid has a mass of 1.4x10(to the fourth power) mg. What is the density of the liquid in g/cm cubed?

Answer 1

1. d=m/v therefore m=dxv m=.02g/ml xcubic meter converted to ml.
2. 25-23=2 error when volume is 25 error is 2
when volume is 100 error is 2x100/25=8%
3. work out on the basis of question 1.
4. work out using th formulae I gave under 1.

Answer 2

1) Okay the purpose in this problem is to cancel out units. We want to cancel out mL and get just grams. A cubic meter is equal to 1000L, therefore, we can do the math like this:

(0.2g/mL) * (1000mL/1L) * (1000L) = 200,000 grams or 200 kilograms


2)With percent error you use this formula:

100% * (25 - 23) / (23) = 8.7% error
When using this in the future you take the absolute value of the numerator. So for instance you could have done 23-25 which is -2 and taken the absolute value to get 2 and still gotten the same answer.


3) Again you want to cancel units so you manipulate the fraction to help you out. So we flip 0.70g/mL to be mL/0.70g and multiply that by 700g to get: 1000 mL


4) Since it is 2.70g per cm, and you have a cube with 1cm on each edge, that means the volume of that cube is 1cm^3 and therefore you can say it is 2.7g (the density) :-).


5) First we want to convert g to mg so we use this:

1.4x10^4mg * (1g / 1000mg) = 14g (we canceled out mg and got grams)
Now we just take 14 and divide it by 10 and get 1.4g / cm^3


Hope this helped!!!!!

Answer 3

All of your questions are based on the same formula

D = M/V

Where D is the density, M is the mass in grams and V is the volume.

Beyond that you have to do some conversions.

You should know that 1 ml = 1 cm3.

You can do the rest