Answer:
B
Explanation:
This is because exothermic reactions occurs when bnds are formed, and involves the release of energy.
Endothermic reaction occur when bonds are broken,and involves absorption of energy.
3Mg + N₂= Mg₃N₂
n(Mg)=12,2g÷<span>24,4g/mol=0,5mol-limiting reagent
</span>n(N₂)=5,16g÷28g/mol=0,18mol
n(Mg₃N₂):n(Mg)=1:3, n(Mg₃N₂)=0,166mol, m(Mg₃N₂)=0,166·101,2=16,8g.
%(N)= 2·Ar(N)÷Mr(Mg₃N₂) = 2·14÷101,2=27,66%=0,2766
%(Mg) = 3·Ar(Mg)÷Mr(Mg₃N₂)= 3·24,4÷101,2=72,34% or 100% - 27,66%= 72,34%.
The pH unit has 10x as many hydrogens ions as the unit above.
Ex: A pH of 5 would have 10x more hydrogen ions than a pH of 6
and 100x more than if it had a pH of 7.
With a pH of 9 and 3, this is equivalent to 10⁶
So your answer should be:
1,000,000
Answer:- 0.88
Solution:- Masses of silver and copper metals are given and we are asked to calculate the percentage of silver in the alloy.
mass percent of Ag = 
Mass of Ag = 17.6 g
mass of Cu = 2.40 g
mass of alloy = 17.6 g + 2.40 g = 20.0 g
Let's plug in the values in the formula:
mass percentage of Ag = 
mass percentage of Ag = 88%
So, the mass percentage of silver in sterling silver is 88% and in decimal form it is 0.88.
Okay
40ml-35ml=5ml
5ml is the volume of the rock
1ml=1cm3
hence the volume of the rock is 5cm3
