First of all, the answer has 3 places of accuracy.
The formula for pH is
pH = - log[H+]
Given: Ph = 3.20
Solution
3.20 = - log[H+]
Divide by - 1
-3.20 = log[H+]
Take the antilog of both sides
10^-3.20 = [H+]
[H+]= 6.30 * 10^-4 moles/L This is a measure of concentration.
It can also be written as 0.000630 moles/L
Answer:
A. 74g/mol
B. 37.8%
Explanation:
A. Determination of the molar mass of dimethylnitrosamine, (CH3)2N2O.
The molar mass of dimethylnitrosamine, (CH3)2N2O can be obtained by adding the atomic masses of the elements present in the compound. This is illustrated below:
Molar mass of (CH3)2N2O = 2[12+ (3x1)] + (2x14) + 16
= 2[12 + 3] + 28 + 16
= 2[15] + 28 + 16
= 30 + 28 + 16
= 74g/mol.
B. Determination of the percentage composition of N in the compound. This is illustrated below:
There are 2 atoms of N in (CH3)2N2O. Mass of N in (CH3)2N2O = 2 x 14 = 28g
Mass of (CH3)2N2O = 74g
%N = Mass of N / mass of (CH3)2N2O x 100
%N = 28/74 x100
%N = 37.8%
Answer:
no
Explanation:
Acidic oxides, or acid anhydride, are oxides that react with water to form an acid, or with a base to form a salt. They are oxides of either nonmetals or of metals in high oxidation states.
Answer:
1) HCl reagent was added in excess
Explanation:
The equation of the reaction is given as;
Zn + HCl --> ZnCl2 + H2
From the stoichiometry;
1 mol of Zn reacts with 1 mol of HCl
In 2g of Zn;
mass = 2
Molar mass = 65.38g/mol
Number of moles = Mass/ Molar mass = 2 / 65.38 = 0.03059 mol
In 10ml of HCl;
the number of moles is: moles = Concentration * Volume = (10 moles/L) (0.0100 L) = 0.10 moles
Comparing 0.03059 mol of Zn : 0.10 mol of HC with the stochiometry, we can deduce that HCl is by far greater. Hence the correct option is option 1.