Horizontal if I am correct
A. H2
B. I2
C. N2
D. O2
An element which is solid at STP that is standard temperature and pressure is iodine.
An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.Elements combine to form compounds.
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Answer:
-909.3KJ/mole
Explanation:
The heat of reaction is accessible from the heat of formation of reactants and products using the formula below:
ΔH = Σ ΔHf products - Σ ΔHf reactants
Before we proceed, it is important to know that the enthalpy of formation of element is zero ,be it a single element or a molecule of an element.
From the reaction for the formation of sulphuric acid, we know we need to know the heat of formation of sulphur (vi) oxide and water. The examiner is quite generous and have us for water already.
Now we need to calculate for sulphur (vi) oxide. This is calculated as follows:
We first calculate for sulphur(iv)oxide. This can be obtained from the reaction between sulphur and oxygen. The calculation goes thus:
ΔH = Σ ΔHf products - Σ ΔHf reactants
ΔH = [ 1 mole suphur(iv) oxide × x] - [ (1 mole of elemental sulphur × 0) + (1 mole of elemental oxygen × 0]
We were already told this is equal to -296.8KJ. Hence the heat of formation of sulphur(iv) oxide is -296.8KJ.
We then proceed to the second stage.
Now, here we have 1 mole sulphur (iv) oxide reacting with 0.5 mole oxygen molecule.
We go again :
ΔH = Σ ΔHf products - Σ ΔHf reactants
ΔH = [ 1 mole of sulphur (vi) oxide × y] - [ (1 mole of sulphur (iv) oxide × -296.8) + (0.5 mole of oxygen × 0)].
We already know that the ΔH here equals -98.9KJ.
Hence, -98.9 = y + 296.8
y = -296.8KJ - 98.9KJ = -395.7KJ
We now proceed to the final part of the calculation which ironically comes first in the series of sentences.
Now, we want to calculate the standard heat of formation for sulphuric acid. From the reaction, we can see that one mole of sulphur (vi) oxide, reacted with one mole of water to yield one mole of sulphuric acid.
Mathematically, we go again :
ΔH = Σ ΔHf products - Σ ΔHf reactants
ΔH = [ 1 mole of sulphuric acid × z] - [( 1 mole of sulphur vi oxide × -395.7) + ( 1 mole of water × -285.8)].
Now, we know that the ΔH for this particular reaction is -227.8KJ
We then proceed to to open the bracket.
-227.8 = z - (-395.7 - 285.8)
-227.8 = z - ( -681.5)
-227.8 = z + 681.5
z = -227.8-681.5 = -909.3KJ
Hence, ΔH∘f for sulphuric acid is -909.3KJ/mol
Answer:
1.18 moles of CS₂ are produced by the reaction.
Explanation:
We present the reaction:
5C + 2SO₂ → CS₂ + 4CO
5 moles of carbon react to 2 moles of sulfur dioxide in order to produce 1 mol of carbon disulfide and 4 moles of carbon monoxide.
As we do not have data from the SO₂, we assume this as the excess reagent. We convert the mass of carbon to moles:
70.8 g / 12 g/mol = 5.9 moles
Ratio is 5:1, so 5 moles of carbon react to produce 1 mol of CS₂
Then, 5.9 moles will produce (5.9 . 1) / 5 = 1.18 moles
2)mass, charge, energy
3) charge, volume, density
4) charge, volume, energy
Answer: It's B this will help u