Answer:
0.075
Explanation:
First obtain the mean of the measurement;
Mean = 10.15 + 9.95 + 9.99 + 10.02/4 = 10.03
Then obtain d^2= (mean-score)^2 for each score;
(10.15-10.03)^2 = 0.0144
(9.95-10.03)^2 = 0.0064
(9.99-10.03)^2 = 0.0016
(10.02-10.03)^2= 0.0001
∑d^2= 0.0144 + 0.0064 + 0.0016 + 0.0001
∑d^2= 0.0225
Variance = ∑d^2/N = 0.0225/4 = 0.005625
Standard deviation= √0.005625
Standard deviation= 0.075
The reactions of the human body are exothermic
Answer:
1.03
Explanation:
You would take 0.00103 and move the decimal like this; 0001.03, we wouldn't have the zeroes in front of the one, as it can throw us off. Therefore, your answer would be 1.03.
Hope I helped! Don't hesitate to let me know if I made a mistake.
Answer:
see explanation below
Explanation:
First to all, this is a redox reaction, and the reaction taking place is the following:
2KMnO4 + 3H2SO4 + 5H2O2 -----> 2MnSO4 + K2SO4 + 8H2O + 5O2
According to this reaction, we can see that the mole ratio between the peroxide and the permangante is 5:2. Therefore, if the titration required 21.3 mL to reach the equivalence point, then, the moles would be:
MhVh = MpVp
h would be the hydrogen peroxide, and p the permanganate.
But like it was stated before, the mole ratio is 5:2 so:
5MhVh = 2MpVp
Replacing moles:
5nh = 2MpVp
Now, we just have to replace the given data:
nh = 2MpVp/5
nh = 2 * 1.68 * 0.0213 / 5
nh = 0.0143 moles
Now to get the mass, we just need the molecular mass of the peroxide:
MM = 2*1 + 2*16 = 34 g/mol
Finally the mass:
m = 0.0143 * 34
m = 0.4862 g
