Answer:

Explanation:
First, we need to find the molecular mass of water (H₂O).
H₂O has:
- 2 Hydrogen atoms (subscript of 2)
- 1 Oxygen atom (implied subscript of 1)
Use the Periodic Table to find the mass of hydrogen and oxygen. Then, multiply by the number of atoms of the element.
- Hydrogen: 1.0079 g/mol
- Oxygen: 15.9994 g/mol
There are 2 hydrogen atoms, so multiply the mass by 2.
- 2 Hydrogen: (1.0079 g/mol)(2)= 2.0158 g/mol
Now, find the mass of H₂O. Add the mass of 2 hydrogen atoms and 1 oxygen atom.
- 2.0158 g/mol + 15.9994 g/mol = 18.0152 g/mol
Next, find the amount of moles using the molecular mass we just calculated. Set up a ratio.

Multiply. The grams of H₂O will cancel out.



The original measurement given had two significant figures (3,2). We must round to have 2 significant figures. All the zeroes before the 1 are not significant. So, round to the ten thousandth.
The 7 in the hundred thousandth place tells us to round up.

There are about <u>0.0018 moles in 0.032 grams.</u>
Answer:
6 x 10⁵ kg Hg
Explanation:
The mass of mercury in the entire lake is found by multiplying the concentration of the mercury by the volume of the lake.
The volume of the lake is calculated in cubic feet:
V = (SA)x(depth) = (100mi²)(5280ft/mi)² x (20ft) = 5.57568 x 10¹⁰ ft³
Cubic feet are then converted to mL (1cm³=1mL)
(5.57568 x 10¹⁰ ft³) x (12in/ft)³ x (2.54cm/in)³ = 1.578856752 x 10¹⁵ mL
The mass of mercury is then found:
m = CV = (0.4μg/mL)(1g/10⁶μg)(1kg/1000g) x (1.578856752 x 10¹⁵ mL) = 6 x 10⁵ kg Hg
Answer:HNO₃ and NO³⁻ would not function as buffer
Explanation:
The buffer solution are usually prepared by using any weak acid (which would partially dissociate) and mixing this weak acid with its own conjugate base or any weak base (which would partially dissociate) and mixing with with its conjugate acid.
A buffer solution is a solution which resists change in pH of the solution.
Since nitric acid is a very strong acid and hence neither nitric acid HNO₃ or its conjugate base NO³⁻ anionb is suitable for the preparation of buffer solution.
HCO³⁻ is a weak acid and hence it can form a buffer solution with its conjugate base CO₃²-. so they can be used to form buffer.
C₂H₅COOH is a weak acid and hence it can also form buffer solution with its conjugate base.
So only HNO₃and NO³⁻ would not be able to form buffer
So option a is the answer.
Hi!
In collision theory, for a chemical reaction to occur - there must be <em>sufficient </em>energy to break down chemical bonds.
We call this the activation energy, as it's the energy needed to <em>activate </em>a chemical reaction!
Hopefully, this helps! =)