CH4 + 2 O2 ---> CO2 + 2 H2O Q = 891,6 kJ / mol CH4
1 mol CH4 = 16 g
16 g ---- 891,6 kJ
x g ----- 272 kJ
x = 272 kJ × 16 g / 891,6 kJ = 4,88 g
You must burn 4,88 g of CH4.
:-) ;-)
Answer:
Answer D => E°(Mg°/Cu⁺²) = 0.34 + 2.37 = 2.71v
Explanation:
(Oxidation) => Mg°(s) => Mg⁺²(aq) + 2e⁻ E°(Mg°/Mg⁺²) = -2.37 v
(Reduction) => Cu⁺²(aq) + 2e⁻ => Cu°(s) E°(Cu⁺²/Cu°) = +0.34 v
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Net Rxn => Mg°(s) + Cu⁺²(aq) => Mg⁺²(aq) + Cu°(s)
Std Cell Potential (25°C/1Atm) = E°(Redn) = E°(Oxidn) = +0.34v - (-2.37v)
= 0.34v + 2.37v = 2.72v
The 1st one. Fertilizers are like food for plants, and that's what an algae is, sorta. Trout's don't eat algae and if there's too much algae around, it gets dirty and they eventually die because of the amount of bacteria in the algae. It's the same thing if you have a fish tank.
Answer : The ages of the brother and sister are, 10 and 16 years respectively.
Solution :
Let the age of brother be 'x' and the age of sister be 'y'
There are two equations formed which are,
x + y = 26 ..........(1)
3y - 4x = 8 ..........(2)
First we have to multiple equation (1) by 4 and then added equation (1) and (2), we get the value of 'y'.

Now put the value of 'y' in equation (2), we get the value of 'x'
3(16) - 4x = 8
4x = 40
x = 10
The age of brother = x = 10 years
The age of sister = y = 16 years
Therefore, the ages of the brother and sister are, 10 and 16 years respectively.