For each item, choose whether the change is a physical change or chemical change

shusha [124]

Bleach Hope this helps have a good day

8 0

3 years ago

A cell was prepared by dipping a Cu wire and a saturated calomel electrode into 0.10 M CuSO4 solution. The Cu wire was attached

Rashid [163]

Answer:

(a) Cu²⁺ +2e⁻ ⇌ Cu

(c) 0.07 V

Explanation:

(a) Cu half-reaction

Cu²⁺ + 2e⁻ ⇌ Cu

(c) Cell voltage

The standard reduction potentials for the half-reactions are+

E°/V

Cu²⁺ + 2e⁻ ⇌ Cu; 0.34

Hg₂Cl₂ + 2e⁻ ⇌ 2Hg + 2Cl⁻; 0.241

The equation for the cell reaction is

E°/V

Cu²⁺(0.1 mol·L⁻¹) + 2e⁻ ⇌ Cu; 0.34

2Hg + 2Cl⁻ ⇌ Hg₂Cl₂ + 2e⁻; -0.241

Cu²⁺(0.1 mol·L⁻¹) + 2Hg + 2Cl⁻ ⇌ Cu + Hg₂Cl₂; 0.10

The concentration is not 1 mol·L⁻¹, so we must use the Nernst equation

(ii) Calculations:

T = 25 + 273.15 = 298.15 K

$Q = \dfrac{\text{[Cl}^{-}]^{2}}{ \text{[Cu}^{2+}]} = \dfrac{1}{0.1} = 10\\\\E = 0.10 - \left (\dfrac{8.314 \times 298.15 }{2 \times 96485}\right ) \ln(10)\\\\=0.010 -0.01285 \times 2.3 = 0.10 - 0.03 = \textbf{0.07 V}\\\text{The cell potential is }\large\boxed{\textbf{0.07 V}}$

3 0

3 years ago

How much heat is required to convert 12. 0 g of ice at -10. 0 ºc to steam at 100. 0 ºc?

nordsb [41]

Main Answer:

Given data:

Mass of ice m = 12 grams = 12/1000 = 0.012 kg

Specific heat s = 4.18 KJ/ gm-1 C-1

Change in temperature t = t2 - t1

t = 100 - (-10)

t = 100 + 10 = 110C

Heat required Q = m x s x t

Q = 0.012 x 4.18 x 110

Q = 5.5176 KJ

Explanation:

What is heat?

Heat is defined as one of the forms of energy. It is a kinetic energy which can be transferred from one object to another object or medium. It cannot be destroyed or created. The units of heat is Joules in SI system and calories in CGS system.

To know more about heat, please visit:

brainly.com/question/13439286

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8 0

2 years ago

When both –NH2 and –COOH replace hydrogen atoms on the same carbon atom, a(n) ____ is formed. a. amine c. carboxylic acid b. ami

Mice21 [21]

$-NH_{2}$ represents amine functional group and $COOH$ represents carboxylic acid functional group. When these both functional groups are substituted onto a single carbon atom, then amino acid is formed.