pH=6.98
Explanation:
This is a very interesting question because it tests your understanding of what it means to have a dynamic equilibrium going on in solution.
As you know, pure water undergoes self-ionization to form hydronium ions, H3O+, and hydroxide anions, OH−.
2H2O(l]⇌H3O+(aq]+OH−(aq]→ very important!
At room temperature, the value of water's ionization constant, KW, is equal to 10−14. This means that you have
KW=[H3O+]⋅[OH−]=10−14
Since the concentrations of hydronium and hydroxide ions are equal for pure water, you will have
[H3O+]=√10−14=10−7M
The pH of pure water will thus be
pH=−log([H3O+])
pH=−log(10−7)=7
Now, let's assume that you're working with a 1.0-L solution of pure water and you add some 10
Answer:
The volume of the gasoline in the tank is 18.85 cubic feet
Explanation:
The tank is a cylinder. The equation for calculating the cylinder volumen is πr²*h, r is radius and h is height. π is approximately 3.1416. So, The tank is resting horizontally on its side, its radius is 2 feet/2= 1 feet. h=a tank long= 6 feet.
With equation:
Vol gasoline=3.1416*1²*6=18.85 feet ³
I hope my answer helps you
Answer:
Explanation:
3.
Knowns: 100mL of solution; concentration of 0.7M
Unknown: number of moles
Equation: number of moles = volume * concentration
Plug and Chug: number of moles = 100/1000 * 0.7 = 0.07 mole
Final Answer: 0.07mole
2.
Knowns: 5.50L of solution; concentration of 0.400M
Unknown: number of moles
Equation: number of moles = volume * concentration
Plug and Chug: number of moles = 5.5 * 0.4 = 2.20 mole
Final Answer: 2.20 mole
The correct answer is False
Remember that:
number of moles = mass/molar mass
First, we get the molar mass of the nitrogen gas molecule:
It is known the the nitrogen gas is composed of two nitrogen atoms, each with molar mass 14 gm (from the periodic table)
Therefore, molar mass of nitrogen gas = 14 x 2 = 28 gm
Second we calculate the mass of the precipitate:
we have number of moles = 0.03 moles (given)
and molar mass = 28 gm (calculated)
Using the equation mentioned before,
mass = number of moles x molar mass = 0.03 x 28 = 0.84 gm
