True or false? All producers are at the top of the food web

H2SO4 is a strong acid because the first proton ionizes 100%. The Ka of the second proton is 1.1x10-2. What would be the pH of a

forsale [732]

Question options:

a) 2.05

b) 0.963

c) 0.955

d) 1.00

Answer:

b) 0.963

Explanation:

H2SO4→ HSO4- + H3O+

HSO4- + H2O ⇌ SO42- + H3O+

Construct ICE table:

HSO4- (aq) + H2O ⇌ SO42- (aq) + H3O+ (aq)

I 0.1 solid & 0 0.1

C -x liquid + x + x

E 0.1 - x are ignored x 0.1 + x

Calculate x

Ka = products/reactants

= $\frac{[SO42-] [H3O+]}{[HSO4-]}$

0.011 = $\frac{x (0.1 + x)}{0.1 - x}$

0.011 x (0.1 -x) = o.1x + x^2

0.0011 - 0.011 x - o.1x - x^2 = 0

0.0011 - 0.011 x - x^2 = 0

Use formula to solve for quadratic equation

x = ${ -b +,-\sqrt{b^2 - 4ac$ / 2a

a = -1, b = -0.111, c = 0.001

Solve for x

x = $\sqrt[-(-o.111)]{(-0.111)^2 - 4(-1) (0.0011) }$ / 2(-1)

x = 0.111 +,- $\sqrt{0.012321 + 0.0044}$ / -2

x = 0.111 +,- $\sqrt{0.016721}$ / -2

x = $\frac{0.111 +, - 0.1293}{-2}$

x = $\frac{0.111 + 0.1293}{-2}$ , x = $\frac{0.111 - 0.1293}{-2}$

x = $\frac{0.2403}{-2}$ , x = $\frac{0.0183}{-2}$

x = - 0.12015 , x = 0.00915

x cannot be negative, so

x = 0.00915 M

Calculate [H3O+]

[H3O+] = 0.1 M + x

[H3O+] = 0.1 M + 0.00915 M

[H3O+] = 0.10915 M

Clculate pH

pH = - log [ H3O+]

pH = - log [ 0.10915]

pH = 0.963

8 0

3 years ago

A scuba diver releases a balloon containing 181 L of helium attached to a tray of artifacts at an underwater archaeological stat

grigory [225]

The first step is to use the formula from Boyle's Law.
[(351 L)(1.0 atm)]/(181L) = 1.94 atm.
To determine the depth of the location where the diver was working, 1.94 is multiplied by 10. Therefore, the location of the underwater archaeological site is 19.4 meters below the surface.

5 0

3 years ago

Read 2 more answers

5. If 4 moles of nitrogen gas reacts with excess hydrogen gas, how many moles of NH3 will be produced?

Setler [38]

The answer is A, hope it helps!

8 0

3 years ago

A 0.4657 g sample of a pure soluble bromide compound is dissolved in water, and all of the bromide ion is precipitated as AgBr b

Yanka [14]

Answer:

The mass percentage of bromine in the original compound is 81,12%

Explanation:

Step 1: Calculate moles AgBr

moles AgBr = mass AgBr / molar mass AgBr

= 0.8878 g / 187.77 g/mol

= 0.00472812 moles AgBr

⇒

Since 1 mol AgBr contains 1 mol Br-

Then the amount of moles Br- in the original sample must also have been 0.00472812 moles

Step 2: Calculating mass Br-

mass Br- = molar mass Br x moles Br-

= 79.904 g/mol x 0.00472812 mol

= 0.377796 g Br-

⇒

There were 0.377796 g Br- in the original sample

Step 3: Calculating mass percentage Br-

⇒mass percentage = actual mass Br- / total mass x 100%

% mass Br = 0.377796 g / 0.4657 g x 100 %

= 81.12%

7 0

3 years ago

Attractions between polarized molecules (intermolecular bonding) are called ____________ bonds and can also form between polariz

elena-s [515]

Polar molecules are characterize by an imbalance of electrostatic forces between the molecules. It arises when the electronegativity of the elements differ greatly. Since there is a great difference of the partial charges, the intermolecular or intramolecular force involved here is the electrostatic bond.

8 0

3 years ago