Answer:
5.46 M
Explanation:
First, we need to know the molar mass of the citric acid, the molar masses of the elements are:
H = 1 g/mol
C = 12 g/mol
O = 16 g/mol
So the molar mass of the acid is: 8x1 + 6x12 + 7x16 = 192 g/mol
The mass of the acid is the number of moles multiplied by the molar mass, so:
m = 0.688x192 = 132.096 g
Then, the volume is the mass divided by the concentration:
V = 132.096/1.049 = 125.926 mL = 0.1259 L
So, the molar concentration is the number of moles divided by the volume in liters:
M = 0.688/0.1259
M = 5.46 M
Answer:
3 examples are beetles, a fly, and bees. Others include ants lady bugs and butterflies
Explanation:
Considering the first reaction there is no NO on the left and NO2 on the right we start with adding equation 1. To remove O3 we subtract equation 2, then here is 1/2O2 left which we remove by subtracting 1/2 equation 3.
That is; Eqn 1 - Eqn 2 - 1/2(Eqn 3)
NO(g) + O3(g) + 3/2 O2(g) + O(g) = NO2(g) + O2(g) + O3(g) + 1/2 O2(g)
This gives;
NO(g) + O(g) = NO2(g) as required, since O3(g) + 3/2O2(g) is on both sides and thus subtracts out.
Hence; ΔH = ΔH1-ΔH2-1/2 ΔH3
= (-198.9 + 142.3 - 0.5×495.0) kJ = -304.1 kJ
Answer: Diatomic elements are a subgroup of diatomic molecules.
Explanation:
Every molecule that consists of two atoms is diatomic. Only if the two atoms are the same there is a diatomic element.
So O2 is a diatomic element (and thus a diatomic molecule)
HCl is a diatomic molecule, but not a diatomic element.
One example of diatomic is earth's atmosphere is a host to a few different diatomic molecules, including nitrogen (N2) and oxygen (O2, not to be confused with ozone, which is O3).
Hopes this helps you!
The number 90 has 1 sig fig.