Answer:
Al 72.61%
Mg 27.39%
Explanation:
To obtain the mass percentages, we need to place the individual masses over the total mass and multiply by 100%.
If we observe clearly, we can see that the parameters given are the moles. We need to convert the moles to mass.
To do this ,we need to multiply the moles by the atomic masses. The atomic mass of aluminum is 27 while that of magnesium is 24.
Now, the mass of aluminum is thus = 27 * 0.0898 = 2.4246g
The mass of magnesium is 0.0381 * 24 = 0.9144g
We can now calculate the mass percentage.
The total mass is 0.9144 + 2.4246 = 3.339g
% mass of Al = 2.4246/3.339 * 100 = 72.61%
% mass of Mg = 0.9144/3.39 * 100 = 27.39%
1. Answer;
Copper (ii) carbonate.
The name of the compound CuCO3 is copper (ii) carbonate.
Explanation;
Cu is the chemical symbol for the copper and CO3 is the chemical symbol for the carbonate group and each one of them has valency of two. Therefore, a compound CuCO3 is formed.
2. Answer;
Yes
Ca2+ reacted with Na2S to form CaS and Na+
Explanation:
Calcium ions reacts with sodium sulfide to form calcium sulfide and sodium ions.
For example; a salt of calcium, calcium carbonate reacts with sodium sulfide to form sodium carbonate and calcium sulfide.
3. Answer;
NaCl and Ag+ do not form a product
Explanation;
The reaction between sodium chloride and silver metal will not take place. This is because silver (Ag) is less reactive than sodium metal and therefore cannot displace sodium from its salt. In other words, silver metal is lower in the reactivity series as compared to sodium metal which indicates sodium metal is more reactive than silver.
4. Answer;
Formation of a white precipitate ; this indicates that silver sulfide is insoluble in water.
Explanation;
When an aqueous solution containing Ag+ ions is added to aqueous solution of sodium sulfide (Na2S), there will be formation of white precipitate. Formation of white precipitate indicates that a reaction has taken place to form a water insoluble compound. The water insoluble compound occurs as a precipitate. The white precipitate is silver sulfide (Ag2S)
2 Ag+ (aq) + Na2S(aq) ----- Ag2S (s) + 2 Na+ (aq)
Answer:
IHD = 0
Explanation:
Given that
C₆H₁₅N
Number of carbon atoms(n) = 6
Number of hydrogen atoms(x') = 15
Number of nitrogen atoms = 1
There is nitrogen atoms then x = x' -1
The index of hydrogen deficiency given as

So


IHD = 0
The index of hydrogen deficiency is zero.
Answer: Option (5) is the correct answer.
Explanation:
An ionic bond is formed by transfer of electrons between the two chemically combining atoms. Whereas a covalent bond is defined as the bond formed by sharing of electrons between the two chemically combining atoms.
When electronegativity difference is from 0.0 to 0.4 then bond formed between the two atoms is non-polar covalent in nature.
When electronegativity difference is greater than 0.4 and less than 1.7 then bond between the two atoms is a polar covalent bond.
When electronegativity difference is 1.7 or greater than the bond formed is ionic in nature.
Therefore, electronegativity difference of the given species is as follows.
Si-P = 2.1 - 1.8 = 0.3
Si-Cl = 3.0 - 1.8 = 1.2
Si-S = 2.5 - 1.8 = 0.7
Thus, we can conclude that given bonds are placed in order of increasing ionic character as follows.
Si-P < Si-S < Si-Cl