Answer: option c an electron has a negative charge and is located outside the nucleus revolving in circular path
Answer:
Molecular formula: C₂H₄O₂
Empirical formula: CH₂O
Explanation:
40 % C, 6.72 % H and 53.29 % O states the centesimal composition of the compound. These data means that in 100 g of compound we have x grams of a determined element.
We divide the mass by the molar mass of each:
40 g / 12 g/mol = 3.33 moles of C
6.72 g / 1 g/mol = 6.72 moles of H
53.29 g / 16 g/mol = 3.33 moles of O
We can determine rules of three to get, the molecular formula.
In 100 g of compound we have 3.33 moles of C, 6.72 moles of H and 3.33 moles of O; therefore in 60 g (1 mol) we must have
- (60 . 3.33) / 100 = 2 moles of C
- (60 . 6.72) / 100 = 4 moles of H
- (60 . 3.33) / 100 = 2 moles of O
Molecular formula is C₂H₄O₂
Empirical formula has the lowest suscripts; we divide by two, so the empirical formula is CH₂O
Answer:
Explanation:
d =
m
V
m = d×V
V =
m
d
DENSITY
Density is defined as mass per unit volume.
d =
m
V
Example:
A brick of salt measuring 10.0 cm x 10.0 cm x 2.00 cm has a mass of 433 g. What is its density?
Step 1: Calculate the volume
V = lwh = 10.0 cm × 10.0 cm × 2.00 cm = 200 cm³
Step 2: Calculate the density
d =
m
V
=
433
g
200
c
m
³
= 2.16 g/cm³
MASS
d =
m
V
We can rearrange this to get the expression for the mass.
m = d×V
Example:
If 500 mL of a liquid has a density of 1.11 g/mL, what is its mass?
m = d×V = 500 mL ×
1.11
g
1
m
L
= 555 g
VOLUME
d =
m
V
We can rearrange this to get the expression for the volume.
V =
m
d
Example:
What is the volume of a bar of gold that has a mass of 14.83 kg. The density of gold is 19.32 g/cm³.
Step 1: Convert kilograms to grams.
14.83 kg ×
1000
g
1
k
g
= 14 830 g
Step 2: Calculate the volume.
V =
m
d
= 14 830 g ×
1
c
m
³
19.32
g
= 767.6 cm³
Molality=mol/kg
342/171
=2m
Hope this helped :)
