Answer:
2.24dm³
Explanation:
Given parameters:
Mass of He = 40g
Unknown:
Volume of Helium = ?
Solution:
To solve this problem, we convert the given mass to number of moles.
Number of moles =
molar mass of He = 4g/mol
Number of moles = = 0.1mole
So;
1 mole of gas at rtp occupies a volume of 22.4dm³
0.1 mole of He will occupy a volume of 0.1 x 22.4 = 2.24dm³
Answer:
42 m/s
Explanation:
To we convert units for speed we can use dimensional analysis. First thing we do is seperate the measurement into a fraction. After this we can multiply by 1km over 0.62137 miles. We do this so that the miles cancel out.
×
=
After this we can use a conversion factor and divide by 3.6.
÷ 3.6 = 42 m/s
Answer:
Density,
Explanation:
It is given that, placing a sample of iron (II) oxide into a graduated cylinder makes the water volume increase 12.0 mL.
It means that the volume of the sample is 12 mL
The weight of the sample is 76.6 g
We need to find the density of the sample.
12 mL = 12 cm³
The formula of density is given by :
So, the density of the sample is .