Percent composition by mass is calculated (mass of element within compound)/(mass of compound)*100. The lower the total molar mass of the compound, the greater the percent composition of sulfur. In this case, MgS would be that compound, since Mg has the lowest molar mass of the four elements bonded to S.
endothermic means it absorbs energy while exothermic means it releases energy. remember this.
Answer:
A chemical change because a temperature change occurred, the solid disappeared and a gas was produces
Explanation:
Magnesium reacts with hydrochloric acid releasing energy, and leading to the formation of magnesium chloride and hydrogen gas. This is represented by the equation below:
Mg₍s₎ + 2HCl₍aq)⇒ MgCl₂₍aq₎ + H₂₍g₎
Answer:
(slow)xy2+z→xy2z (fast) c step1:step2:xy2+z2→xy2z2
Explanation:
Step1: xy2+z2→xy2z2 (slow)
Step2: xy2z2→xy2z+z (fast)
2XY 2 + Z 2 → 2XY 2 Z
Rate= k[xy2][z2]
When the two elementary steps are summed up, the result is equivalent to the stoichiometric equation. Hence, this mechanism is acceptable. The order of both elementary steps is 2, which is ‘≤3’; this also makes this mechanism acceptable. Furthermore, the rate equation aligns with the experimentally determined rate equation, and this also makes this mechanism acceptable. Therefore, since all the three rules have been observed, this mechanism is possible.
Only the amount of gas is held constant.
