Ok this is the question i need help on first

#3. How many liters are in 244 g of Krypton (Kr) gas (83.80 g/mol)?

ValentinkaMS [17]

Explanation:

100 liter because it is measured

5 0

3 years ago

Calculate the equilibrium concentration of H 3 O H3O in a 0.20 M M solution of oxalic acid. Express your answer to two significa

Black_prince [1.1K]

<u>Answer:</u> The equilibrium concentration of $H_3O^+$ ion is $8.3064\times 10^{-2}M$

<u>Explanation:</u>

We are given:

Molarity of oxalic acid solution = 0.20 M

Oxalic acid $(H_2C_2O_4)$ is a weak acid and will dissociate 2 hydrogen ions.

The chemical equation for the first dissociation of oxalic acid follows:

$H_2C_2O_4(aq.)+H_2O\rightleftharpoons H_3O^+(aq.)+HC_2O_4^-(aq.)$

<u>Initial:</u> 0.20

<u>At eqllm:</u> 0.20-x x x

The expression of first equilibrium constant equation follows:

$Ka_1=\frac{[H_3O^+][HC_2O_4^{-}]}{[H_2C_2O_4]}$

We know that:

$Ka_1\text{ for }H_2C_2O_4=0.059$

Putting values in above equation, we get:

$0.059=\frac{x\times x}{(0.20-x)}\\\\x=-0.142,0.083$

Neglecting the negative value of 'x', because concentration cannot be negative.

So, equilibrium concentration of hydronium ion = x = 0.083 M

The chemical equation for the second dissociation of oxalic acid:

$HC_2O_4^-(aq.)+H_2O\rightarrow H_3O^+(aq.)+C_2O_4^{2-}(aq.)$

<u>Initial:</u> 0.083

<u>At eqllm:</u> 0.083-y 0.083+y y

The expression of second equilibrium constant equation follows:

$Ka_2=\frac{[H_3O^+][C_2O_4^{2-}]}{[HC_2O_4^-]}$

We know that:

$Ka_2\text{ for }H_2C_2O_4=6.4\times 10^{-5}$

Putting values in above equation, we get:

$6.4\times 10^{-5}=\frac{(0.083+y)\times y}{(0.083-y)}\\\\y=-0.083,0.0000639$

Neglecting the negative value of 'x', because concentration cannot be negative.

So, equilibrium concentration of hydronium ion = y = 0.0000639 M

Total concentration of hydronium ion = [x + y] = [0.083 + 0.0000639] = 0.0830639 M

Hence, the equilibrium concentration of $H_3O^+$ ion is $8.3064\times 10^{-2}M$

7 0

3 years ago

I need help with empirical formula calculations

AysviL [449]

Answer:

I think it’s onlineeeeeee

Explanation:

7 0

3 years ago

Read 2 more answers

What is the name of the isotope produced when Californium-251 emits an alpha particle?

Charra [1.4K]

<h3>Answer:</h3>

Curium-247 <em>i.e.</em> ²⁴⁷₉₆Cm

<h3>Explanation:</h3>

Alpha decay is given by following general equation,

ᵃₓA → ⁴₂He + ᵃ⁻⁴ₓ₋₂B

Where;

A = Parent Isotope

B = Daughter Isotope

ᵃ = Mass Number

ₓ = Atomic Number

Californium-251 is the parent isotope in our case and it has 98 protons (atomic number) and is given as,

²⁵¹₉₈Cf

The alpha decay reaction of Californium-251 will be as,

²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆B

The symbol for B with atomic number 96 was found to be the atom of Curium (Cm) by inspecting periodic table. Hence, the final equation is as follow,

²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆Cm

3 0

3 years ago

Item 3

svetoff [14.1K]

Answer:

Semiconductors are poor conductors at low temperatures, but their resistance decreases with increasing temperature.

Explanation:

A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;

1. Extrinsic semiconductor.

2. Intrinsic semiconductor.

The statement which best describes the electrical conductivity of metals and semiconductors is that semiconductors are poor conductors at low temperatures, but their resistance decreases with increasing temperature.

This ultimately implies that, semiconductors are typically an insulator (poor conductor) at low temperatures and a good conductor at high temperatures.

Additionally, conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.

6 0

3 years ago