Explanation:
(a) mass number = atomic number + number of neutrons
(the atomic number is the number of protons of an element)
mass number of A = 11 + 12 = 23
mass number of B = 17 + 18 = 35
(b) +1 and -1, respectively
(c) A+ + B- → AB (the first plus sign and the minus sign are superscripts)
The reaction between copper II chloride and sodium sulfide as well as lead II nitrate and potassium sulfate both produce precipitates.
The solubility of a substance in water is in accordance with the solubility rules. It is possible that a solid product may be formed when two aqueous solutions are mixed together. That solid product is referred to as a precipitate.
Now, we will consider each reaction individually to decode whether or not a precipitate is possible.
- In the first reaction, we have; CuCl2(aq) + Na2S(aq) ---->CuS(s) + 2NaCl(aq). A precipitate (CuS) is formed.
- In the second reaction, Pb(NO3)2(aq) + 2KNO3(aq) ----> PbSO4(s) + KNO3(aq), a precipitate PbSO4 is formed
- In the third reaction, NH4Br(aq) + NaOH(aq) ----->NH3(g) + NaBr(aq) + H2O(l), a precipitate is not formed here.
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Does it is a complete qwestion? It
is not clearef
The answer is C. Hydrogen Bond
