We can calculate for the number of moles of NO2 using its molar mass 46.0055 g/mol: 11.5 g NO2 (1 mol NO2 / 46.0055 g NO2) = 0.250 mol NO2
We use the mole ratio of O2 and NO2 from their coefficients in the balanced chemical equation 2Pb(NO3)2(s) <span>→</span> 2PbO(s) + 4NO2(g) + O2 (g) which is one mole O2 is to react with four moles of NO2, to compute for the number of moles of oxygen: 0.250 mol NO2 (1 mol O2 / 4 mol NO2) = 0.0625 mol O2
We can now calculate for the mass of oxygen O2 using its molar mass: 0.0625 mol O2 (31.998 g O2 / 1 mol O2) = 2.0 grams O2 Therefore, 2.0 grams of oxygen is produced.
The clock now has potential energy. When the alarm rings, the potential energy is converted into kinetic energy and sound energy.
Alarm clock runs due to the electrical energy. Due to the electric current, the electric motor rotates the blade. It means that the electrical energy is converted into mechanical energy.
The mechanical energy finally generates vibrations which cause sound.
Thus, energy transformation which takes place in alarm clock will follow the order-
Matter and substance are definitely related. All substances
are matter but all matters are not substance. A matter can consist of numerous
substances. Matter is generally a loose term used in respect to a substance.
Any physical object can be casually called a matter. Matter and substance are
sometimes used for the same context, but it is completely wrong. Numerous
examples have already proved that a matter may or may not be a substance
depending on its physical nature, but a substance is always a matter.
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 )