標題:
F.3 chem urgent
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發問:
which of the following statements are incorrect?? a) the relative molecular mass of Mg oxide is 40 b) the formula mass of a compound is always a whole numberc) the relative molecular mass of a molecule is the relative mass of the molecule on the 12C= 12.00 scale (Relative atomic masses: O = 16, Mg=24)... 顯示更多 which of the following statements are incorrect?? a) the relative molecular mass of Mg oxide is 40 b) the formula mass of a compound is always a whole number c) the relative molecular mass of a molecule is the relative mass of the molecule on the 12C= 12.00 scale (Relative atomic masses: O = 16, Mg=24) Explain Please !!!!
最佳解答:
Ans A is incorrect. Add the sum of the relative atomic masses that given above, the answer is 40. But there are NO molecule in MgO.The correct statement should be the relative FORMULA mass of Mg oxide is 40. C is correct.This is the definition of molecular mass. B is correct.For example, the formula mass of Na2O (sodium oxide) is Na2 O =23x2+16 =62
其他解答:
i think A and B are incorrect~~~~~~ A.Mg oxide is not a molecule.relative molecular mass can't be used. B .Formula mass may not be whole number.because it is sum of the relative mass which relative to carbon12 sacle.so that it will not be a whole number.|||||緊係B 係incorrect!!!! formula mass of a compound 點會係一個whole number!!一定有點數la~ such as Na:39.1
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