Answer:
44 g
Explanation:
The formula for the number of moles (n) is equal to 
.
Since we need to find the mass, we derive it from the formula of the number of moles and we get that mass = n x molecular weight .
The molecular weight of 
= 12 g/mol (from the carbon) + 19x4 g/mol (from the 4 fluorine atoms)= 88 g/mol
We plug in the numbers in the derived formula for the mass and we get :
mass = n x molecular weight = 0.5 mol x 88 g/mol = 44 g
The answer is B, this is a synthesis reaction. A good way to identify a synthesis reaction is when there are multiple reactants, but only one product.
Answer:
The Sun, Earth, and the Moon form a night angle.
Explanation:
Explanation:
Filtration is a separation technique in which solid particles suspended in liquid medium are separated by allowing the mixture through the pores of the filter paper. By this solid particles get collect on filter paper and liquid drains out from the pores of the filter paper.
The chronological order for given steps will be:
- Weigh and fold the filter paper.
- Place the filter paper in the funnel, then place the funnel in the Erlenmeyer flask.
- Allow the solid/liquid mixture to drain through the filter.
- Use water to rinse the filter paper containing the mixture.
- Weigh the dried filter paper and copper.
Answer: CoBr3 < K2SO4 < NH4 Cl
Justification:
1) The depression of the freezing point of a solution is a colligative property, which means that it depends on the number of particles of solute dissolved.
2) The formula for the depression of freezing point is:
ΔTf = i * Kf * m
Where i is the van't Hoof factor which accounts for the dissociation of the solute.
Kf is the freezing molal constant and only depends on the solvent
m is the molality (molal concentration).
3) Since, you are assuming equal concentrations and complete dissociation of the given solutes, the solute with more ions in the molecular formula will result in the solution with higher depression of the freezing point (lower freezing point).
4) These are the dissociations of the given solutes:
a) NH4 Cl (s) --> NH4(+)(aq) + Cl(-) (aq) => 1 mol --> 2 moles
b) Co Br3 (s) --> Co(3+) (aq) + 3Br(-)(aq) => 1 mol --> 4 moles
c) K2SO4 (s) --> 2K(+) (aq) + SO4 (2-) (aq) => 1 mol --> 3 moles
5) So, the rank of solutions by their freezing points is:
CoBr3 < K2SO4 < NH4 Cl
