Answer: 4 x 10 ∧-2 moles of nitrogen.
Explanation:
The chemical formular for quinine is ; C20 H24 N2 O2
As can be seen from the chemical formular;
1 mole of quinine contains 2 moles of Nitrogen
Thus; 2.0 x 10 ∧-2 moles of quinine would contain
2.0 x 10 ∧-2 x 2 = 4 x 10 ∧-2 moles of nitrogen.
Therefore 4 x 10 ∧-2 moles of nitrogen are in 2.0×10−2mole of quinine
The initial temperature is 137.34 °C.
<u>Explanation:</u>
As the specific heat formula says that the heat energy required is directly proportional to the mass and change in temperature of the system.
Q = mcΔT
So, here the mass m is given as 23 kg, the specific heat of steel is given as c = 490 J/kg°C and the initial temperature is required to find with the final temperature being 140 °C. Also the heat energy required is 30,000 J.
ΔT =
ΔT =
Since the difference in temperature is 2.66, then the initial temperature will be
Final temperature - Initial temperature = Change in temperature
140-Initial temperature = 2.66
Initial temperature = 140-2.66 = 137.34 °C
Thus, the initial temperature is 137.34 °C.
Hi I'm in Chemistry too this year,
I believe D is correct because usually physical changes are things like density, color or quantity.
Density is the mass of compound divided by its volume can be shown as follows:


40 mL of snow having 20 g of mass calculated from density.
Now, 10 cm of snow = 3.93 inches = 20 g
As, 10 inches of rain will produce 11 inches of ice as the volume of ice is bigger than rain water.
10 inches rain = 11 inches snow
3.93 inches of snow produced by

Thus, 3.57 incehs of rain produces by 10 cm snow.
Most likely the equation yields a new compound XY. This is a synthesis reaction. <span>Synthesis
reaction is a reaction where two or more substances combine to form a new
compound. It is a reaction which releases energy in the form of heat and
light. Therefore, it is an exothermic reaction.</span>