In an experiement things that are changing are called variables.
Atomic mass of helium is 4.002642g/mol
(542000g)/(4.002642g/mol)*6.02*10^23 = 8.15*10^28 atoms
From the reaction between Cu and HNO₃, the formed gas is NO₂ instead of NO₃. Hence the correct balanced equation would be,
Cu(s) + 4HNO₃(aq) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O<span>(l)
Here, Cu goes to </span>Cu(NO₃)₂ by changing its oxidation number from 0 to +2 while NO₃⁻ goes to NO₂ by reducing its oxidation state from +5 to +4 . Hence Cu is oxidized by HNO₃ in the reaction.
1 kPa = 7.5 mmHg so 7.0 mmHg / 7.5 mmHg x 1 kPa = .93 kPa
101.3 kPa = 1 atm so 10 kPa / 101.3 kPa x 1 atm = .0987 atm
1 kPa = 7.5 mmHg so 15 kPa x 7.5 mmHg / 1 kPa = 112.5 mmHg
The primary form of heat transfer taking place within the water bottle will be convection, which is the natural circulation of fluid due to density differences arising from temperature differences.
The second form is dependent on how the heating is taking place. If the bottle is out in sunlight, the form of heat transfer is radiation from the sun's rays. If heat is directly being applied to it, then the form is conduction, which occurs in solids and through direct contact.
