This form of matter has no definite shape but it has volume.

How does friction affect energy transformation

Westkost [7]

The friction can be used as a stopper for the electricity so it can slow

or it can increace speed

4 0

3 years ago

What is the pH at the equivalence point in the titration of a 25.7 mL sample of a 0.370 M aqueous nitrous acid solution with a 0

expeople1 [14]

Answer:

pH = 8.24

Explanation:

Nitrous acid (HNO₂) reacts with KOH, thus:

HNO₂ + KOH → KNO₂ + H₂O

Moles of HNO₂ are:

0.0257mL ₓ (0.370mol / L) = 0.00951moles.

In equivalence point, the complete moles of nitrous acid reacts with KOH producing potassium nitrite. There are needed:

0.00951mol ₓ (1L / 0.491mol) = 0.01937L ≡ 19.4mL of 0.491M KOH to reach equivalence point.

Total volume in equivalence point is: 19.4mL + 25.7mL = 45.1mL

Potassium nitrite is in equilibrium with water, thus:

NO₂⁻ + H₂O ⇄ HNO₂ + OH⁻

Where equilibrium constant, Kb, is defined as:

Kb = 1.41x10⁻¹¹ = $\frac{[OH^-][HNO_2]}{[NO_2]}$

In equilibrium, molarity of each compound are:

[NO₂⁻]: 0.00951mol/0.00451L - X = 0.211M - X

[HNO₂]: X

[OH⁻]: X

Where X is reaction coordinate

Replacing in Kb:

1.41x10⁻¹¹ = $\frac{[X][X]}{[0.211 -X]}$

0 = X² + 1.41x10⁻¹¹X - 2.97x10⁻¹²

Solving for X:

X = -1.72x10⁻⁶ FALSE ANSWER. There is no negative concentrations.

X = 1.72x10⁻⁶. Right answer.

That means:

[OH⁻]: 1.72x10⁻⁶M

As pOH is -log [OH⁻] and pH = 14-pOH:

pOH = 5.76; pH = 8.24

3 0

3 years ago

Given 8.25 g of butanoic acid and excess ethanol, how many grams of ethyl butyrate would be synthesized, assuming a complete 100

mash [69]

Answer:

10.87 g of Ethyl Butyrate

Solution:

The Balance Chemical Equation is as follow,

H₃C-CH₂-CH₂-COOH + H₃C-CH₂-OH → H₃C-CH₂-CH₂-COO-CH₂-CH₃ + H₂O

According to equation,

88.11 g (1 mol) Butanoic Acid produces = 116.16 g (1 mol) Ethyl Butyrate

So,

8.25 g Butanoic Acid will produce = X g of Ethyl Butyrate

Solving for X,

X = (8.25 g × 116.16 g) ÷ 88.11 g

X = 10.87 g of Ethyl Butyrate

8 0

3 years ago

it is method used to separate particulates from a liquid by allowing in the solids to settle at the bottom of the mixture

wariber [46]

Answer:

Decantation

Explanation:

Decantation is one of the process of separating mixture containing solid and liquid. In this process, gravity plays a very important role. The solid part of the mixture is allowed to settle down. The liquid is removed and separated in another container. It is a process that helps in the purification of the liquid. The particles that are insoluble settles down and is further subject to be separated from the mixture.

5 0

2 years ago

Give the ground-state electron configuration for silicon (SiSi) using noble-gas shorthand. Express your answer in condensed form

nydimaria [60]

Answer:

[Ne] 3s² 3p²

Explanation:

Silicon atoms have 14 electrons. The ground state electron configuration of ground state gaseous neutral silicon is 1s²2s²2p⁶3s²3p².

Using noble gas shorthand, the electronic configuration is reduced to;

[Ne] 3s² 3p². Ne s the nearest noble gas to silicon, Ne contains 8 electrons, this means there's still 4 more electrons to fill. The s orrbital can only hold 2, hence the reaing two is transferred to the p orbital.

5 0

3 years ago