Given: C3H8(g) + O2(g) ----> CO2 (g) + H2O (g)
Step : Put a 3 in front of CO2 (g) to balance C
=> C3H8(g) + O2(g) ----> 3CO2 + H2O to balance H
Step 2: Put a 4 in front of H2O
=> C3H8 (g) + O2(g) -----> 3CO2 (g) + 4H2O (g)
Step 3: Given that there are 3*2 + 4 = 10 O to the right side, put a 5 in front of O2 to balance O:
=> C3H8(g) + 5O2(g) -----> 3CO2(g) + 4H2O(g)
You can verify that the equation is balanced.
So, the answer is that the coefficient in front of O2 is 5.
Answer:
726 torr
Explanation:
Generally, atmospheric pressure can be measured using a manometer which is in form of a U-shaped tube. In addition, 1 mm Hg is equivalent to 1 torr. Therefore, 752 torr is equivalent to 752 mm Hg. Therefore, the total pressure will be equivalent to the atmospheric pressure (mm Hg) + the mercury height.
In this case, the mercury height = -26 mm
Thus:
The helium pressure = 752 - 26 = 726 mm Hg
This is also equivalent to 726 torr
You need to monitor the solution to see when the crystals start gathering at the bottom of the solution. You can slowly add alum until it stops dissolving. The point just before it starts its sedimentation at the bottom is the point when the solution is saturated.
Answer:

Explanation:
Molarity is a measure of concentration in moles per liter.

There are 0.250 moles of sodium hydroxide (NaOH) and 500 milliliters of water. We need to convert milliliters to liters. Remember that 1 liter contains 1000 milliliters.




Now we have the values to solve for molarity:
- moles= 0.250 mol NaOH
- liters= 0.5 L
Substitute the values into the formula.

Divide.

- 1 mole per liter (mol/liter) is equal to 1 Molar or M.
- Our answer of 0.5 moles of sodium hydroxide per liter is equal to 0.5 M NaOH

The molarity of the solution is <u>0.5 M NaOH</u>