1. a. FeS + 2HCl --> FeCl2 + H2S
b. This is a double- replacement reaction. (The elements "switch partners".)
2. a.2Na + F2 --> 2NaF
b. This is a composition/synthesis reaction. (The two reactants are combining or synthesizing to make one product.)
3. a. 2HgO --> 2Hg + O2
b. This is a decomposition reaction. (The single reactant is breaking down or "decomposing" into multiple reactants.)
4. Hydrogen gas reacts with oxygen gas to create water in a composition/synthesis reaction.
I hope these answers will help you! If you need any explanation, ask and hopefully I can get back to you. ;)
<span>293 grams
The formula for the wavelength of a massive particle is
λ = h/p
where
λ = wavelength
h = Plank constant (6.626070040Ă—10^â’34 J*s)
p = momentum (mass times velocity)
So let's solve for momentum and from there get the mass
λ = h/p
λp = h
p = h/λ
Substitute known values and solve
p = 6.626070040Ă—10^â’34 J*s/3.45Ă—10^-34 m
p = 1.92 J*s/m
Since momentum is the product of mass and velocity, we have
p = M * V
p/V = M
So substitute again, and solve.
p/V = M
1.92 J*s/m / 6.55 m/s = M
1.92 kg*m/s / 6.55 m/s = M
1.92 kg*m/s / 6.55 m/s = M
0.293 kg = M
So the mass is 293 grams</span>
<u>Answer:</u> The molality of naphthalene solution is 0.499 m
<u>Explanation:</u>
Density is defined as the ratio of mass and volume of a substance.
......(1)
Given values:
Volume of carbon tetrachloride = 500 mL
Density of carbon tetrachloride = 1.60 g/mL
Putting values in equation 1, we get:

Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg. The formula used to calculate molarity:
.....(2)
Given values:
Given mass of naphthalene = 51.2 g
Molar mass of naphthalene = 128.17 g/mol
Mass of solvent = 800 g
Putting values in equation 2, we get:

Hence, the molality of naphthalene solution is 0.499 m
Answer:
Explanation:
Chemical potential energy is the chemical energy stored (or property) of a substance. One chemical potential energy of wood is combustion. Combustion involves the burning of a substance in excess oxygen (in this case open air). <u>The chemical energy stored here is transformed to thermal/heat energy after combustion due to the large amount of heat evolved/produced</u>.
NOTE:
The model above also that combustion is an exothermic reaction because it involves the release of heat into it's surrounding.