Answer: 120g/mol
Explanation:
The first step we are to take is to calculate the freezing point depression of the solution.
ΔT(f) = freezing point of pure solvent - freezing point of solution
ΔT(f) = 5.48 - 3.77
ΔT(f) = 1.71°C
Next we are to calculate the molal concentration of the solution using freezing point depression
ΔT(f) = K(f) * m
m = ΔT(f)/K(f)
m = 1.71/5.12
m = 0.333 molal
Now, we calculate the molecular weight of the unknown...
m = 0.333 mol = 0.333 mol X per kg of benzene
moles of X = 0.333 mol of X per kg of benzene * 0.5kg of benzene
moles of X = 0.1665
molecular weight of X = 20g of X/0.1665
molecular weight of X = 120/mol
Answer:
D. They have the same number of protons as electrons.
Explanation:
Protons are found in the nucleus of the atom and have a positive charge while electrons orbit around the nucleus and have a negative charge. Usually, in a neutral atom of an element, the number of protons is equal to the number of electrons. This is why the atom has no charge because the positive and negative charges cancel out. When an atom loses an electron its charge turns positive while when it gains an electron its charge turns negative.
The concentrations of a mixture at equilibrium are constant as a function of time because the <span>e forward reaction proceeds at the same rate as the reverse reaction.</span>
Answer:
An inclined plane is a machine because it makes horizontal surface that make easier for us to move objects to higher or lower surfaces.
Answer: The balanced equation is 
.
Explanation:
The given reaction equation is as follows.
Number of atoms present on reactant side are as follows.
- Li = 1
- H = 1
= 1
Number of atoms present on product side are as follows.
- Li = 1
- H = 2
- = 1
To balance this equation, multiply Li by 2 and 
by 2 on reactant side. Also, multiply 
by 2 on product side.
Hence, the equation can be rewritten as follows.
Now, number of atoms present on reactant side are as follows.
- Li = 2
- H = 2
- = 2
Number of atoms present on product side are as follows.
- Li = 2
- H = 2
- = 2
As there are same number of atoms on both reactant and product side. Hence, the equation is now balanced.
Thus, we can conclude that the balanced equation is .
