Answer:

Explanation:
1 mole of any substance contains the same number of particles. The particles can vary (atoms, molecules, formula units), but there are always 6.022*10²³ particles. In this case, the particles are formula units of potassium nitrate or KNO₃.
Let's create a ratio.

Since we are trying to find the formula units in 0.250 moles, we multiply by that number.

The units of moles of potassium nitrate cancel.

The denominator of 1 can be ignored, so we can make a simple multiplication problem.


If we round to the nearest tenth, the 0 in the hundredth place tells us to leave the 5 in the tenth place.

0.250 moles of potassium nitrate is approximately equal to 1.5*10²³ formula units of potassium nitrate and choice B is correct.
Answer:
Liquid oxygen evaporates at only a slightly higher temperature than liquid nitrogen because they have similarly low attraction between molecules. This would mean less liquid oxygen is coming out of tank 3 because some of it is evaporating as a gas instead.
Answer:
you need only one independent variable because if not, you wont know what factors have changed your experiment.
Explanation:
Answer:
200 lb•ft/s
Explanation:
From the question given above, the following data were obtained:
Force (F) = 2 tons
Time (t) = 5 mins
Height (h) = 15 ft
Power (P) =?
Next, we shall convert 2 tons to pound. This can be obtained as follow:
1 ton = 2000 lb
Therefore,
2 tons = 2 × 2000
2 tons = 4000 lb
Next, we shall convert 5 mins to seconds. This can be obtained as follow:
1 min = 60 s
Therefore,
5 mins = 5 × 60
5 mins = 300 s
Finally, we shall determine the power of the pump. This can be obtained as follow:
Force (F) = 4000 lb
Time (t) = 300 s
Height (h) = 15 ft
Power (P) =?
P = F × h / t
P = 4000 × 15 / 300
P = 60000 / 300
P = 200 lb•ft/s
Thus, the power of the pump is 200 lb•ft/s