PLEASE HELP ME WHATS THE ANSWER

A car engine produces 604 kJ of mechanical energy from fuel capable of producing 2416 kJ of energy. The efficiency of the engine

Anna71 [15]

I think it’s 40% but I’m not sure

6 0

3 years ago

How many grams of solid potassium hypochlorite should be added to 2.00 L of a 0.244 M hypochlorous acid solution to prepare a bu

Olin [163]

Answer:

8.2763 g

Explanation:

Considering the Henderson- Hasselbalch equation for the calculation of the pH of the buffer solution as:

pH=pKa+log[base]/[acid]

Where Ka is the dissociation constant of the acid.

Given that the acid dissociation constant = 3.5×10⁻⁸

pKa = - log (Ka) = - log (3.5×10⁻⁸) = 7.46

Given concentration of acid = [acid] = 0.244 M

pH = 6.733

So,

6.733 = 7.46+log[base]/0.244

[Base] = 0.0457 M

Given that Volume = 2 L

So, Moles = Molarity × Volume

Moles = 0.0457 × 2 = 0.0914 moles

Molar mass of potassium hypochlorite = 90.55 g/mol

Mass = Moles × Molar mass = (0.0914 × 90.55) g = <u>8.2763 g</u>

7 0

4 years ago

PLEASE HELPPPPPPPP

Pavlova-9 [17]

Answer:

3 factors that are required for biodegradation are

a) Appropriate moisture

b) Oxygen supply

c) Stable condition

Explanation:

For biodegradation in a landfill, following conditions are essential –

a) Appropriate moisture

b) Oxygen supply

c) Stable condition

Contrast to above three conditions, the waste in landfill is kept dry, devoid of oxygen supply, and stirred continuously due to which the organic matter mummify instead of decomposing.

6 0

3 years ago

Calculate the solubility of CaF2 in g/L (Ksp = 4.0 x 10-8). 2. What is the pH of a solution containing a hydrogen ion concentrat

Pepsi [2]

Answer:

$\large \boxed{1. \text{ 0.17 g/L; 2. 3.52; 3. Cl; 4. (a) +3; (b) +4; (c) +6}}$

Explanation:

1. Solubility of CaF_2

(a) Molar solubility

CaF₂ ⇌ Ca²⁺ + 2F⁻

$K_{\text{sp }} = \text{[Ca$^{2+}$]}\text{[F$^{-}$]}^{2}= 4.0 \times 10^{-8}\\s(2s)^{2}=4.0 \times 10^{-8}\\4s^{3} = 4.0 \times 10^{-8}\\s^{3} = 1.0 \times 10^{-8}\\s =2.2 \times 10^{-3}\text{ mol/L}$

(b) Mass solubility

$\text{Solubility} = 2.2 \times 10^{-3} \text{ mol/L} \times \dfrac{\text{78.07 g}}{\text{1 L }} = \text{0.17 g/L}\\\\\text{The solubility of CaF$_{2}$ is $\large \boxed{\textbf{0.17 g/L}}$}$

2. pH

pH = -log [H⁺] = -log(3.0 × 10⁻⁴) = 3.52

3. Oxidizing and reducing agents

Zn + Cl₂ ⟶ ZnCl₂

$\rm \stackrel{\hbox{0}}{\hbox{Zn}} + \stackrel{\hbox{0}}{\hbox{ Cl}_{2} }\longrightarrow \stackrel{\hbox{+2}}{\hbox{Zn}}\stackrel{\hbox{-1}}{\hbox{Cl}_{2}}$