Answer:
35.9%
Explanation:
The percent volume of the coffee solution can be calculated as follows:
% volume of coffee solution = volume of coffee/total volume of coffee solution × 100
According to this question, a cup of coffee has 71 mL of coffee and 127 mL of water. This means that, the total volume of coffee solution is;
71mL + 127mL = 198mL
% volume = 71/198 × 100
= 0.359 × 100
Percent volume of coffee solution = 35.9%
Answer:
116 years
Explanation:
To solve this, we will use the half life equation;
A(t) = A_o(½)^(t/t_½)
Where;
A(t) is the amount of strontium left after t years;
A_o is the initial quantity of strontium that will undergo decay;
t_½ is the half-life of strontium
t is the time it will take to decay
We are given;
A(t) = 7.5 g
A_o = 120 g
From online values, half life of strontium-90 is 29 years. Thus, t_½ = 29
Thus;
7.5 = 120 × ½^(t/29)
Divide both sides by 120 to get;
7.5/120 = ½^(t/29)
0.0625 = ½^(t/29)
In 0.0625 = (t/29) In ½
-2.772589 = (t/29) × (-0.693147)
(t/29) = -2.772589/(-0.693147)
t/29 = 4
t = 29 × 4
t = 116 years
Answer:
WCl₂, WCl₄, WCl₅, WCl₆
Explanation:
Molar Mass of Tungsten = 184 g/mol
Mass of Chlorine = 35.5 g/mol
In the first compound;
Percentage of tungsten = 72.17 %
Upon solving;
72.17 % = 184
100 % = Total mass
Total mass of compound = 254.95g
Mass of chlorine = 254.95 - 184 = 70.95 (Dividing by 35.35; This is approximately 2 Chlorine atoms.
The Formular is WCl₂
In the second compound;
Percentage of tungsten = 56.45 %
Upon solving;
56.45 % = 184
100 % = Total mass
Total mass of compound = 325.95 g
Mass of chlorine = 325.95 - 184 = 141.95g (Dividing by 35.35; This is approximately 4 Chlorine atoms.
The Formular is WCl₄
In the third compound;
Percentage of tungsten = 50.91 %
Upon solving;
50.91 % = 184
100 % = Total mass
Total mass of compound = 361.42 g
Mass of chlorine = 361.42 - 184 = 177.42 (Dividing by 35.35; This is approximately 5 Chlorine atoms.
The Formular is WCl₅
In the fourth compound;
Percentage of tungsten = 46.39 %
Upon solving;
46.39 % = 184
100 % = Total mass
Total mass of compound = 396.64 g
Mass of chlorine = 396.64 - 184 = 212.64 (Dividing by 35.35; This is approximately 6 Chlorine atoms.
The Formular is WCl₆
There is 1 aluminium atom and 4 polonium atoms
The Lysosome is marked with an x
