Answer:
Explanation:
Atom X,
Neutron num = 4, Mass num = 7
Therefore, proton number = Mass num - Neutron num
= 7 - 4
= 3
Atom Y,
Neutron num = 5, Mass num = 9
Therefore, proton number = Mass num - Neutron num
= 9 - 5
= 4
1) False. Atom X belongs to group 3 while atom Y belongs to group 4
2) False. Atom X is in a column on the left of Atom Y
3) True. Atom X and atom Y belong to the same period two on the periodic table
4) Fasle. Atom X and Y are not isotopes because they do not have the same atomic number.
Isotopy is a phenomenon whereby atom of same element have same atomic number but different mass number
Answer:
Electron
Explanation:
The answer would be the electron because it is constantly moving so its location cannot be accurately determined
Answer:
129.73 g of CaBr₂
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
CaBr₂ + 2KOH –> Ca(OH)₂ + 2KBr
Next, we shall determine the mass of CaBr₂ that reacted and the mass of Ca(OH)₂ produced from the balanced equation. This can be obtained as follow:
Molar mass of CaBr₂ = 40 + (80×2)
= 40 + 160
= 200 g/mol
Mass of CaBr₂ from the balanced equation = 1 × 200 = 200 g
Molar mass of Ca(OH)₂ = 40 + 2(16 + 1)
= 40 + 2(17)
= 40 + 34
= 74 g/mol
Mass of Ca(OH)₂ from the balanced equation = 1 × 74 = 74 g
SUMMARY :
From the balanced equation above,
200 g of CaBr₂ reacted to produce 74 g of Ca(OH)₂.
Finally, we shall determine the mass of CaBr₂ that react when 48 g of Ca(OH)₂ were produced. This can be obtained as follow:
From the balanced equation above,
200 g of CaBr₂ reacted to produce 74 g of Ca(OH)₂.
Therefore, Xg of CaBr₂ will react to produce 48 g of Ca(OH)₂ i.e
Xg of CaBr₂ = (200 × 48)/74
Xg of CaBr₂ = 129.73 g
Thus, 129.73 g of CaBr₂ were consumed.
Methane is the compound CH4, and burning it uses the reaction:
CH4 + O2 -> CO2 + H2O, which is rather exothermic. To find the heat released by burning a certain amount of the substance, you should look at the bond enthalpy of each compound, and then compare the values before and after the reaction. In methane, there are 4 C-H bonds, which have bond energy of 416 kj/mol, resulting in a total bond energy of 1664 kj/mol. O2 is 494 kj/mol. Therefore we have a total of 2080 kj/mol on the left side. On the right side we have CO2, which has 2 C=O bonds, each at 799 kj/mol each, resulting in 1598 kj/mol, and H2O has 2 O-H bonds, at 459kj/mol each, resulting in a total of 2516 kj/mol on the right hand side. Now, this may be confusing because the left hand side seems to have less heat than the right, but you just need to remember: making minus breaking, which results in a total change of 436kj/mol heat evolved.
Now it is a simple matter of find the mols of CH4 reacted, using n=m/mr.
n = 9.5/16.042 = 0.592195 mol
Therefore, if we reacted 0.592195 mol, and we produced 436 kj for one mol, the total amount of energy evolved was 436*<span>0.592195 kj, or 258.197 kj.</span>
