Solution is not a pure substance b/c it is mixture of two substance
Answer:
"1 M" will be the right solution.
Explanation:
The given values are:
Number of moles,
= 2 moles
Volume of solution,
= 2000 mL
or,
= 2 L
Now,
The molarity of the solution will be:
= 
On substituting the values, we get
= 
= 
Answer:
Incorrect
Explanation:
Given that,
The mass of a boulder, m = 22 kg
We need to find the weight of the student in pounds.
We know that,
1 pound = 454 g
or
1 g = (1/454 pounds)
22 kg = 0.022 grams
So,
0.022 grams = 
= 0.000048 pounds
The student says the weight is 0.048 pounds. It means he was incorrect.
The answer is <span>b. 1% H, 42% Cl, 57% O.</span>
Let's first calculate a molar mass (M) of HClO₃. <span>Molar mass is a mass of 1 mole of a substance. It can be expressed as the sum of relative atomic masses (Ar), which are masses of atoms of the elements:
</span>M(HClO₃) = Ar(H) + Ar(Cl) + 3Ar(O)
Ar(H) = 1 u
Ar(Cl) = 35.5 u
Ar(O) = 16 u
M(HClO₃) = Ar(H) + Ar(Cl) + 3Ar(O) = 1 + 35.5 + 3 · <span>16 = 84.5 u
Now, we just need to calculate mass percent of each element using the proportion:
Ar : x = M : 100% </span>⇒ x = Ar ÷ M · 100%
Hydrogen: x = Ar(H) ÷ M · 100% = 1 ÷ 84.5 · 100% = 1.2% ≈ 1%
Chlorine: x = Ar(Cl) ÷ M · 100% = 35.5 ÷ 84.5 <span>· 100% = 42%
</span>Oxygen: x = 3Ar(O) ÷ M · 100% = 48 ÷ 84.5 · 100% = 56.8% ≈ 57%
