The most probable answer is: (a) <span>The black pot emits heat at a faster rate than the silver pot. It means the black pot conducts heat at a higher rate than the silver pot, that's why it cooled off faster. It also means that the silver pot retains heat better and is more of an insulator.</span>
answer=H+]=10-7
explain=the same way, a solution with a pH of 5 contains 10-5mol/l of hydrogen ions, a solution with a pH of 6 contains 10-6mol/l of hydrogen ions, while the solution with a pH of 7 contains 10-7mol/l of hydrogen ions
If we are talking about moles then the answer to that is 0.22
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.
:-) ;-)
