Answer:
Q8) True
Q9) First ionization energy
Q10) Metal oxides
Explanation:
A common property of group one elements (alkali metals) is their combination with water to form basic solutions. E.g 2K(s)+2H2O(l)→2KOH(aq)+H2(g).
The distance of the outermost electron in the atom from the nucleus is inversely related to the first ionization energy. As the distance between the outermost electron and the nucleus in group 17 elements gets larger, the corresponding first ionization energies of elements in the group gets smaller.
Group 1 elements can combine with oxygen to give metal oxides. E.g 4K + O2 --> 2 K2O
The answer is: b)16,200 seconds :)
Answer:
Explanation:
To neutralize a chemical to a pH of 7 before discarding, one would require a significant amount of acids or bases. Our best guess is that the solution in itself is either an acid or a base. Neutralization with the right amount of a proper reagent can bring the pH of the solution to a neutral 7.
If the solution has a pH originally greater than 7, add a corresponding amount of acid to it. This will reduce the concentration and bring it to a neutral point. Provided one is dealing with a solution of pH less than 7, simply add a base to to bring the solution to neutrality.
Δ H reaction = q / n where q: amount of heat released and n is number of moles of substance.
q = m . C . ΔT where:
m = mass of substance (g)
C = Specific heat capacity (4.18)
ΔT = change in temperature = 24.25 - 23.16 = 1.09
q = 1000 x 4.18 x 1.09 = 4556 J = 4.556 kJ
number of moles (n) = Molarity (M) x Volume (L)
= 0.185 M x 0.07 L = 0.01295 mole
Δ H = q / n = - (4.556 kJ / 0.01295 mole) = -351.8 kJ / mol
Note: it is exothermic reaction (-ve sign) i.e. temperature is raised