Number of moles of NO2 = 11.5/(14+16x2) =0.250mol Mole ratio: 4NO2 to 1O2 Number of moles of O2=0.250/4 =0.0625mol Mass of O2 produced= 0.0625x32 =2g Answer: B
The combined gas law states that the pressure of a gas is inversely related to the volume and directly related to the temperature. If temperature is held constant, the equation is reduced to Boyle's law. Therefore, if you decrease the pressure of a fixed amount of gas, its volume will increase.
The question is incomplete. The complete question is :
In science, we like to develop explanations that we can use to predict the outcome of events and phenomena. Try to develop an explanation that tells how much NaOH needs to be added to a beaker of HCl to cause the color to change. Your explanation can be something like: The color change will occur when [some amount] of NaOH is added because the color change occurs when [some condition]. The goal for your explanation is that it describes the outcome of this example, but can also be used to predict the outcome of other examples of this phenomenon. Here's an example explanation: The color of the solution will change when 40 ml of NaOH is added to a beaker of HCl because the color always changes when 40ml of base is added. Although this explanation works for this example, it probably won't work in examples where the flask contains a different amount of HCl, such as 30ml. Try to make an explanation that accurately predicts the outcome of other versions of this phenomenon.
Solution :
Consider the equation of the reaction between NaOH and
NaOH (aq) + HCl (aq) → NaCl(aq) +
The above equation tells us that of reacts with of .
So at the equivalence point, the moles of NaOH added = moles of present.
If the volume of the taken = mL and the conc. of = mole/L
The volume of NaOH added up to the color change = mole/L
Moles of taken = moles.
The color change will occur when the moles of NaOH added is equal to the moles of taken.
Thus when
or when
or mL of NaOH added, we observe the color change.
Where are the volume and molarity of the taken.
is the molarity of NaOH added.
When both the NaOH and are of the same concentrations, i.e. if , then
Or the 40 mL of will need 40 mL of NaOH for a color change and
30 mL of would need 30 mL of NaOH for the color change (provided the concentration )
The Mass Number is the combination of the amount of Protons and Neutrons in an element, so if the total mass is 222, and the amount of protons is 86, then you can do 86 + x = 222 to find that x is equal to 136