The empirical formula of this compound is 
<h3>Empirical formula </h3>
To calculate the empirical formula of a compound, the value of moles of each element is needed.
As we have the information of the mass value, we will use the molar mass expression, which corresponds to:





As the value of the empirical formula must be an integer, simply multiply the two values by a common factor:


So, the empirical formula of this compound is
.
Learn more about empirical formula: brainly.com/question/1247523
Answer: 0.0009 moles of octane were used up.
Explanation:
To calculate the moles :
Given mass of octane = 0.1 g
Molar mass of octane = 11.23 g/mol
Putting in the values we get:

Thus 0.0009 moles of octane were used up.
Answer: D. To decrease the total moles of gas in the system
Explanation:
Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.
This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.
when the pressure is increased, , the volume will decrease according to Boyle's Law. Now, according to the Le-Chatelier's principle, the equilibrium will shift in the direction where decrease in pressure is taking place.
As the pressure is directly proportional to the number of moles of gas molecules. So, the equilibrium will shift in a direction where the total moles of gas are decreasing.
Thus the correct answer is to decrease the total moles of gas in the system.
Answer:
C. A Spring Scale
Explanation:
Using process of elimination, we can quickly decide that a stopwatch and a ruler will not be useful in measuring the force. This leaves us with either the spring scale or a balance scale. A balance scale is used to compare two weights, so this is eliminated. That leaves us with a spring scale. This is because we can attached the spring scale to the car and when we let it go, we can record the force. I hope this helps!
Answer:
The solid crystals disappeared
Explanation:
When a soluble solid solute is added to water, the solid solute disappears after a little while. The disappearance of this solute indicates that the solute has been dissolved in water.
In this case, blue copper sulphate crystals are added to water, the blue crystals disappear leaving only a blue solution. The disappearance of these blue copper sulphate crystals indicates that the substance has dissolved in water.