The balanced equation for the given reaction:
C₆H₁₂O₆ (glucose) + 6O₂→ 6CO₂ + 6H₂O
So in the balanced equation the coefficients before glucose, oxygen, water and carbon dioxide are 1, 6, 6 and 6 respectively.
Therefore, the sum of the coefficients in the balanced equation
= 1 + 6 + 6 + 6
= 19
The correct answer is 19.
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Answer:
pOH= 14.248
[H+]=1.77 M
[OH-]=5.65 x10^-15M
Explanation:
pH+pOH= 14
pOH= 14-pH
pOH=14-(-0.248)
pOH= 14.248
[H+]=10^-pH= 10^-(-0.248)=1.77 M
[OH-]=10^-pOH= 10^-14.248=5.65 x10^-15M
Answer:
a) a0 was 46.2 grams
b) It will take 259 years
c) The fossil is 1845 years old
Explanation:
<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>
A = A0 * (1/2)^(t/h)
⇒ with A = the final amount = 46.2 grams
⇒ A0 = the original amount
⇒ t = time = 8 hours
⇒ h = half-life time = 3.2 hours
46.2 = Ao*(1/2)^(8/3.2)
Ao = 261.35 grams
<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>
t = (ln(0.66))-0.693) * 432 = 259 years
It will take 259 years
<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>
<em />
t = (ln(0.80))-0.693) * 5730 = 1845
The fossil is 1845 years old
Answer:
A. The increase in the mass of the magnesium oxide was due to oxygen atoms in the air.
Explanation:
Burning occurs in the presence of oxygen. A chemical combination occurs between Mg and O in that the atom of magnesium attracts one another.
Mg + O₂ → MgO
Starting with the magnesium, on reacting with oxygen a new compound forms. This is why there is mass increase in the MgO compared to the starting material.
