All categories

3 years ago

Please help me :D I’m begging rn lol

Chemistry

1 answer:

Dahasolnce [82]3 years ago

5 0

Answer:

To catch a ball, the fielder has to stop the ball. This means, force is applied against the motion of the ball. So, between the fielder applies force on the ball and the ball comes to rest, the ball moves in the direction opposite to the direction of force. Thus work is negative.

Explanation:

MARK ME AS BRAINLIEST PLSSS

You might be interested in

A man swims for 30 minutes at a speed of 109m/min how far does he swim

allochka39001 [22]

Answer:

3270m

Explanation:

1 minute= 109m

30 minutes= 109 × 30 = 3270m

(whatever you do on one side you have to do to the other)

hope this helps :)

5 0

3 years ago

Which one of the following solutions will have the greatest concentration of hydroxide ions?

jek_recluse [69]

Answer:

e = 0.250 M calcium hydroxide

it will produce 0.5 M [OH⁻].

Explanation:

A = 0.100 M HCl

HCl is an acid it would produce negligible amount of OH⁻.

B = 0.100 M magnesium hydroxide

Mg(OH)₂ + H₂O → Mg²⁺ + 2OH⁻

The ration of Mg(OH)₂ and OH⁻ is 1:2.

[OH⁻] = 2× 0.100 = 0.200 M

C =0.100 M ammonia

NH₃ + H₂O → NH₄OH → NH₄⁺ + OH⁻

The Kb expression will be written as,

Kb = [NH₄⁺] [OH⁻] / [NH₃]

Kb = 1.8 ×10 ⁻⁵

Now we will put the values:

1.8 ×10 ⁻⁵ = [NH₄⁺] [OH⁻] / 0.100

[NH₄⁺] [OH⁻] = x²

1.8 ×10 ⁻⁵ = x² / 0.100

x² = 1.8 ×10 ⁻⁵ × 0.100

x² = 1.8 × 10 ⁻⁶

x = 1.34 × 10 ⁻³

[OH⁻] = 1.34 × 10 ⁻³ M

d = 0.300 M rubidium hydroxide

RbOH + H₂O → Rb⁺ + OH⁻

The ratio of RbOH and OH⁻ is 1:1.

[OH⁻] = 0.300 M

e = 0.250 M calcium hydroxide

Ca(OH)₂ + H₂O → Ca²⁺ + 2OH⁻

The ration of Ca(OH)₂ and OH⁻ is 1:2.

[OH⁻] = 2× 0.250 = 0.5 M

7 0

3 years ago

What are the products of the acid-base reaction between HNO3 and NaOH? A. H2O and NaNO3 B. NaH and NO3OH C. HNOH and NaO3 D. NaO

Otrada [13]

Answer:- A. $H_2O$ and $NaNO_3$

Explanations:- In general, $acid+base\rightarrow salt+water$

In acid-base reaction the acid gives hydrogen ion and the base gives hydroxide ion and these ions combine to form water. Rest of the ions from acid and base combine to form the salt.

Nitric acid breaks to give hydrogen ion and nitrate ion. Similarly, NaOH breaks to give sodium ion and hydroxide ion. Since, hydrogen ion and hydroxide ions form water, the sodium ion and nitrate ion forms the salt, sodium nitrate.

The reaction is shown as:

$HNO_3(aq)+NaOH(aq)\rightarrow NaNO_3(aq)+H_2O(l)$

So, the right choice is A.

5 0

3 years ago

Which of the following is an example of ionization of an acid?

Amiraneli [1.4K]

Answer:

NH3(g) + H2O(1) → NH4+(aq) + OH (aq)

HF(aq) + H2O(1) → H3O+(aq) + F (aq)

Explanation:

Acid-base reactions are chemical reactions involving acids and bases. Acids tend to ionize/dissociate in water, a property which determines their strength. Ionization of an acid refers to the acid losing its hydrogen ion (H+) in water solution. An acid ionizes or dissociates to form a conjugate base.

A strong acid is so because it ionizes completely in water i.e. loses all its hydrogen ion (H+) while a weak acid partially ionizes in water.

In the chemical reactions;

1) NH3(g) + H2O(1) → NH4+(aq) + OH (aq)

H20 loses its hydrogen ion (H+) in this reaction to form an anion (OH-). Hence, water (H20) is an acid in this case which ionizes to form a conjugate base (OH-). This is an example of ionization of acid.

2) HF(aq) + H2O(1) → H3O+(aq) + F (aq)

Hydrogen fluoride (HF) loses its hydrogen ion (H+) in the presence of water to form anion (F-). The HF is the acid while F- is it's conjugate base. Thus, an example of ionization of acid

4 0

3 years ago

A buffer solution is made up of acetic acid (CH3COOH) and sodium acetate (NaCH3COO). The major equilibria in the buffer system a

katrin [286]

The equilibria showing how the acetate buffer adjusts to addition of a small amount of NaOH is:

CH3COOH(aq) + H2O(1) → H30+ (aq) + CH3COO (aq)

<h3>What is a buffer?</h3>

A buffer is a solution which resists changes to its pH when small amounts of strong base or acid is added to it.

Buffers are made from solutions of weak acids and their salts or weak bases and their salts.

The equilibria showing how a buffer made from acetic acid and sodium acetate (NaCH3COO) adjusts to addition of a small amount of NaOH is as follows:

CH3COOH(aq) + H2O(1) → H30+ (aq) + CH3COO (aq)

Addition of NaOH, a strong base will neutralize the hydronium ion, causing the acetic acid ionization equilibrium to shift to the right to produce more of the acetate ion, the conjugate base.

Learn more about acetate buffer at: brainly.com/question/17490438

3 0

2 years ago