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2 years ago

Please help???? i dont know this

Chemistry

2 answers:

xeze [42]2 years ago

7 0

Answer:

a and b

Explanation:

Nesterboy [21]2 years ago

4 0

Answer:

The after-rain smell is produced by an interaction between rain and the oils released by plants. Due to chemical reaction between the rain water and oils secreted out by the plants

A homemade volcano can be created by combining baking soda and vinegar. When it erupts, carbon dioxide gas is released. When vinegar reacts with baking soda carbon-dioxide gas is released.

The Statue of Liberty has turned green over time due to the reaction of copper with ,oxygen,carbon dioxide and water.

Explanation:

Chemical change is defined as those change in which arrangement of atoms present in the substance changes and leads to formation of new substance.

The after-rain smell is produced by an interaction between rain and the oils released by plants. Due to chemical reaction between the rain water and oils secreted out by the plants

A homemade volcano can be created by combining baking soda and vinegar. When it erupts, carbon dioxide gas is released. When vinegar reacts with baking soda carbon-dioxide gas is released.

$CH_{3} COOH+ NaHCO_3$ → $CO_2+H_2O+CH_3COONa$

The Statue of Liberty has turned green over time due to the reaction of copper with ,oxygen,carbon dioxide and water.

$Cu+O_2+CO_2+H_2O$ → $Cu_2(OH)_2CO_3$

Physical change is defined as those changes which leads to change in shape, size or state of the substance changes. No new substance is formed.

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The correct mathematical expression for finding the molar solubility (s) of sn(oh)2 is:

lara [203]

Answer is: Ksp = 4s³.
Balanced chemical reaction (dissociation) of strontium hydroxide:
Sr(OH)₂(s) → Sr²⁺(aq) + 2OH⁻(aq).
Ksp(Sr(OH)₂) = [Sr²⁺]·[OH⁻]².
[Sr²⁺] = s.
[OH⁻] = [Sr²⁺] = 2s
Ksp = (2s)² · x = 4s³.
Ksp is the solubility product constant for a solid substance dissolving in an aqueous solution.
[Sr²⁺] is equilibrium concentration of iumcations.
[OH⁻] is equilibrium concentration of hydroxide anions.

7 0

2 years ago

Explain why the first ionization energy K is less than that of Ca

Ainat [17]

Answer:

The first ionization energy for K is less than Ca because Ca has a larger effective nuclear charge.

5 0

3 years ago

Part A

Roman55 [17]

These are two questions and two answers

Question 1.

Answer:

7.33 × 10 ⁻³ c

Explanation:

1) Data:

a) m = 9.11 × 10⁻³¹ kg

b) λ = 3.31 × 10⁻¹⁰ m

c) c = 3.00 10⁸ m/s

d) s = ?

2) Formula:

The wavelength (λ), the speed (s), and the mass (m) of the particles are reltated by the Einstein-Planck's equation:

λ = h / (m.s)

h is Planck's constant: h= 6.626×10⁻³⁴J.s

3) Solution:

Solve for s:

s = h / (m.λ)

Substitute:

s = 6.626×10⁻³⁴J.s / ( 9.11 × 10⁻³¹ kg × 3.31 × 10⁻¹⁰ m) = 2.20 × 10 ⁶ m/s

To express the speed relative to the speed of light, divide by c = 3.00 10⁸ m/s

s = 2.20 × 10 ⁶ m/s / 3.00 10⁸ m/s = 7.33 × 10 ⁻³

Answer: s = 7.33 × 10 ⁻³ c

Question 2.

Answer:

2.06 × 10 ⁻³⁴ m.

Explanation:

1) Data:

a) m = 45.9 g (0.0459 kg)

b) s = 70.0 m/s

b) λ = ?

2) Formula:

Macroscopic matter follows the same Einstein-Planck's equation, but the wavelength is so small that cannot be detected:

λ = h / (m.s)

h is Planck's constant: h= 6.626×10⁻³⁴J.s

3) Solution:

λ = h / (m.s)

Substitute:

λ = 6.626×10⁻³⁴J.s / ( 0.0459 kg × 70.0 m/s) = 2.06 × 10 ⁻³⁴ m

As you see, that is tiny number and explains why the wave nature of the golf ball is undetectable.

Answer: 2.06 × 10 ⁻³⁴ m.

5 0

2 years ago

write the equation that matches the description one atom of zinc reacts with one atom of sulfur to yield one molecule of zinc su

Elis [28]

Answer: Zn + S —> ZnS

Explanation:

3 0

2 years ago

Classify the four reactions that your group analyzed today as being either endothermic or exothermic

ArbitrLikvidat [17]

Chemical reactions are basically divided into two major classes depending on whether the reaction lose energy or gain energy from the environment during the course of the reaction. The two classes of reaction are exothermic and endothermic reaction.
An exothermic reaction is a type of reaction in which the reaction system lose energy to the environment and thus, the energy content of the reactants is more than that of the product formed. Because of this, the enthapyl change of an exothermic reaction is always negative.
An endothermic reaction is a type of reaction in which the reaction system absorb energy from the environment. Thus, the energy contents of the products is always higher than that of the reactants and the enthapyl change of the reaction is always positive. During the course of the reaction, the reaction container is usually cold to the touch because energy is been absorbed from the environment.

4 0

2 years ago