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ahrayia [7]
2 years ago
8

All elements have a AHf, of ___

Chemistry
1 answer:
stellarik [79]2 years ago
7 0

All elements have a AHf, of <u>0</u>

kJ/mole at standard temperature and pressure.

<h3>What is an element?</h3>

An element can be defined as a substance which cannot be split into two or more simpler forms by an ordinary chemical process

Below are the list of the first twenty elements:

  • Hydrogen
  • Helium
  • Lithium
  • Berylium
  • Boron
  • Carbon
  • Nitrogen
  • Oxygen
  • Fluorine
  • Neon
  • Sodium
  • Magnesium
  • Aluminum
  • Silicon
  • Phosphorus
  • Sulphur
  • Chlorine
  • Argon
  • Potassium
  • Calcium

So therefore, all elements have a AHf, of <u>0</u>

kJ/mole at standard temperature and pressure.

Learn more about elements:

brainly.com/question/11829854

#SPJ1

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For this exercise, you can simulate the described conditions by changing the values in the run experiment tool of the simulation
Furkat [3]
1) ideal gas law: p·V = n·R·T.
p - pressure of gas.
V -volume of gas.
n - amount of substance.
R - universal gas constant.
T - temperature of gas.
n₁ = 0,04 mol, V₁ = 0,06 l.
n₂ = 0,07 mol, V₂ = 0,06 · 0,07 ÷ 0,04 = 0,105 l.
2) V₁ = 0,06 l, T₁ = 240,00 K.
T₂ = 340,00 K, V₂ = 340 · 0,06 ÷ 240 = 0,05 l.
3 0
2 years ago
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If a compound contains a poly atomic ion then what type of compound is it A. Convalent Compound B. Ionic Compound
den301095 [7]

Answer:

B. Ionic Compound

Explanation:

An ionic compound is that compound which contains a positively charged ion called CATION and a negatively charged ion called ANION. The cation loses or transfers electrons to the anion, hence, making the former (cation) positive and the latter (anion) negative.

A polyatomic ion is an ion that contains more than one type of atom e.g OH-, NO3²-, CO3²- etc. A polyatomic ion usually has an overall charge formed from the charges of the individual atoms that makes it up. For example, in OH-, the overall charge is -1.

Since a polyatomic ion can have an overall positive or negative charge, it must enter a reaction with another ion that complements it i.e. a negative polyatomic ion will react with a positive ion to neutralize its charge. Hence, this forms an IONIC COMPOUND. This is why most compounds with polyatomic ions are IONIC COMPOUNDS.

For example, CaCO3 is an ionic compound formed when Ca²+ (cation) reacts with the polyatomic anion: CO3²-

5 0
2 years ago
A mixture of water and graphite is heated to 600 K in a 1 L container. When the system comes to equilibrium it contains 0.17 mol
Kryger [21]

Answer:

0.44 moles

Explanation:

Given that :

A mixture of water and graphite is heated to 600 K in a 1 L container. When the system comes to equilibrium it contains 0.17 mol of H2, 0.17 mol of CO, 0.74 mol of H2O, and some graphite.

The equilibrium constant K_c=  \dfrac{[CO][H_2]}{[H_2O]}

The equilibrium constant  K_c=  \dfrac{(0.17 )(0.17)}{0.74}

The equilibrium constant K_c=  0.03905

Some O2 is added to the system and a spark is applied so that the H2 reacts completely with the O2.

The equation for the reaction is :

H_2 + \dfrac{1}{2}O_2 \to H_2O \\ \\ 0.17 \ \ \ \ \  \ \ \ \ \to0.17

Total mole of water now = 0.74+0.17

Total mole of water now = 0.91 moles

Again:

K_c=  \dfrac{[CO][H_2]}{[H_2O]}

0.03905 =  \dfrac{[0.17+x][x]}{[0.91 -x]}

0.03905(0.91 -x) = (0.17 +x)(x)

0.0355355 - 0.03905x = 0.17x + x²

0.0355355 +0.13095 x -x²

x² - 0.13095 x - 0.0355355 = 0

By using quadratic formula

x = 0.265  or   x = -0.134

Going by the value with the positive integer; x = 0.265 moles

Total moles of CO in the flask when the system returns to equilibrium is :

= 0.17 + x

= 0.17 + 0.265

= 0.435 moles

=0.44 moles (to two significant figures)

3 0
3 years ago
A boy with pneumonia has lungs with a volume of 1.7 L that fill with 0.070 mol of air when he inhales. When he exhales, his lung
BlackZzzverrR [31]

Answer:

0.053moles

Explanation:

Hello,

To calculate the number of moles of gas remaining in his after he exhale, we'll have to use Avogadro's law which states that the volume of a given mass of gas is directly proportional to its number of moles provided that temperature and pressure are kept constant. Mathematically,

V = kN, k = V / N

V1 / N1 = V2 / N2= V3 / N3 = Vx / Nx

V1 = 1.7L

N1 = 0.070mol

V2 = 1.3L

N2 = ?

From the above equation,

V1 / N1 = V2 / N2

Make N2 the subject of formula

N2 = (N1 × V2) / V1

N2 = (0.07 × 1.3) / 1.7

N2 = 0.053mol

The number of moles of gas in his lungs when he exhale is 0.053 moles

7 0
3 years ago
Purest form of carbon is
vladimir2022 [97]

Answer:

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4 0
3 years ago
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