What do you need help on?
HCl is a strong acid and so dissociates fully in water:
HCl(aq) --> H+(aq) + Cl-(aq)
Since there is a 1:1 mole ratio between HCl and H+ in this reaction, the number of moles of H+ = number of moles of HCl. The number of moles of HCl can be calculated as moles = mass/RMM = 0.80g / 36.5g/mol = 0.022mol.
Since 5.5 l of solution is made, the concentration of H+ is:
[H+] = 0.022mol / 5.5l = 0.004M. This can then be used to calculate pH through the equation pH = -log[H+] = -log(0.004) = 2.40
The mass of 2.64 moles of water is 47.56 grams
Answer: They are arranged by atomic number.
Traditionally they include boron from group 3A, silicon and germanium in group 4A, aresnic and antimony in group 5A and tellurium from group 6A, although sometimes selenium, astatine, polonium and even bismuth have also been considered as metalloids. Typically metalloids are brittle and show a semi-metallic luster.
The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium. Five elements are less frequently so classified: carbon, aluminium, selenium, polonium, and astatine.
