The question is incomplete, here is the complete question:
Consider the following reaction: 
In the first 15.0 s of the reaction, 1.9×10⁻² mol of O₂ is produced in a reaction vessel with a volume of 0.480 L . What is the average rate of the reaction over this time interval?
<u>Answer:</u> The average rate of appearance of oxygen gas is 
<u>Explanation:</u>
We are given:
Moles of oxygen gas = 
Volume of solution = 0.480 L
Molarity is calculated by using the equation:
So, 
The given chemical reaction follows:
The average rate of the reaction for appearance of 
is given as:
![\text{Average rate of appearance of }O_2=\frac{\Delta [O_2]}{\Delta t}](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20rate%20of%20appearance%20of%20%7DO_2%3D%5Cfrac%7B%5CDelta%20%5BO_2%5D%7D%7B%5CDelta%20t%7D)
Or,
where,
= final concentration of oxygen gas = 0.0396 M
= initial concentration of oxygen gas = 0 M
= final time = 15.0 s
= initial time = 0 s
Putting values in above equation, we get:
Hence, the average rate of appearance of oxygen gas is
Answer: The mole ratio of oxygen to pentane for the combustion of pentane is 8 : 1.
Explanation: The given reaction is a type of combustion reaction.
Combustion reaction is a reaction in which a hydrocarbon reacts with oxygen gas to produce water and carbon dioxide gas.
For the reaction of pentane with oxygen, the balanced equation would be:
In the reaction, 1 mole of 
reacts with 8 moles of gas.
Thus giving us the mole ratio as
Oxygen : Pentane = 8 : 1
Answer:
4
Explanation:
it will share its valence electrons with other elements to acquire noble gas confriguration of the nearest inert element.
Hello Gary!
*Sorry if I'm late*
Your answer is going to be 65.
Element A (which is actually Zinc) has the atomic number of 65. (I remember having got memorize this also).
Pretty much the explanation is that the number of patrons is equivalent to the element's atomic number!
Hope this helps!
Have a nice day :D
Answer:
The mass of zinc sulfide produced is 
Explanation:
From the question we are told that
The mass of zinc is 
The mass of sulfur is 
The molar mass of 
is a constant with value 65.39 g /mol
The molar mass of 
is a constant with value 32.01 g/mol
The molar mass of 
is a constant with value 97.46 g/mol
The reaction is
So from the reaction
1 mole of react with 1 mole of to produce 1 mole of
This implies that
65.39 g /mol of react with 32.01 g/mol of to produce 97.46 g/mol of
From the values given we can deduce that the limiting reactant is sulfur cause of the smaller mass
So
0.250 g of react with 0.250 of to produce 
of
So
Thus the mass of the mass of zinc sulfide produced is
