Answer: D
Explanation:
Light waves travel in straight paths called rays. Unlike sound, where waves have to travel through matter to be heard, light waves do not have to travel through matter to be seen. Instead, rays travel in a straight path until they hit an object. A ray's straight path is the path of light
Explanation:
Molar mass of
= 39.1 + 35.5 + 3(16.0) = 122.6 g
Molar mass of KCl = 39.1 + 35.5 = 74.6 g
Molar mass of
= 32.0 g
According to the equation, 2 moles of
reacts to give 3 moles of oxygen.
Therefore, 2 (122.6) = 245.2 g of
will give 3 (32.0) = 96.0 g of oxygen. Thus, 245.2 g of
gives 96.0 g of oxygen.
(a) Calculate the amount of oxygen given by 2.72 g of
as follows.
of
(b) Calculate the amount of oxygen given by 0.361 g of
as follows.
of
c) Calculate the amount of oxygen given by 83.6 kg
as follows.
of 
Convert kg into grams as follows.
= 32731 g of 
(d) Calculate the amount of oxygen given by 22.5 mg of
as follows.

Convert mg into grams as follows.
of 
Answer:
of 0.056 M HF solution is 
Explanation:
cM 0 0
So dissociation constant will be:
Give c= 0.056 M and
= ?
Putting in the values we get:
Thus
of 0.056 M HF solution is 
Consider this balanced chemical equation:
2 H2 + O2 → 2 H2O
We interpret this as “two molecules of hydrogen react with one molecule of oxygen to make two molecules of water.” The chemical equation is balanced as long as the coefficients are in the ratio 2:1:2. For instance, this chemical equation is also balanced:
100 H2 + 50 O2 → 100 H2O
This equation is not conventional—because convention says that we use the lowest ratio of coefficients—but it is balanced. So is this chemical equation:
5,000 H2 + 2,500 O2 → 5,000 H2O
Again, this is not conventional, but it is still balanced. Suppose we use a much larger number:
12.044 × 1023 H2 + 6.022 × 1023 O2 → 12.044 × 1023 H2O
These coefficients are also in the ratio of 2:1:2. But these numbers are related to the number of things in a mole: the first and last numbers are two times Avogadro’s number, while the second number is Avogadro’s number. That means that the first and last numbers represent 2 mol, while the middle number is just 1 mol. Well, why not just use the number of moles in balancing the chemical equation?
2 H2 + O2 → 2 H2O
They do form directly on the equators