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Gelneren [198K]
1 year ago
8

Question 2 Classify the following statement as a prediction, observation, theory, or law. Please be sure to classify the stateme

nt exactly as it is written! A helium filled balloon floats.
Chemistry
1 answer:
vredina [299]1 year ago
5 0

Answer:

Theory

Explanation:

We are given the statement;

"A helium filled balloon floats."

Now, this statement is an attempt to explain to us why balloons float. And the reason is because they are filled with helium. This is no prediction or law or observation because to find out if the balloons contain helium, there must have been experiments to confirm that.

Thus, the statement in the question is a theory.

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Butane (c4h10) undergoes combustion in excess oxygen to generate gaseous carbon dioxide and water. given δh°f[c4h10(g)] = –124.7
vagabundo [1.1K]

The value of Δ H butane (g) = -124.7 kJ/mol

The value of Δ H CO2 (g) = -393.5 kJ/mol

The value of Δ H H2O (g) = -241.8 kJ/mol

Mass of butane, m = 8.30 gm

Molar mass of butane is 58 gm/mol

Consider the reaction,

C₄H₁₀ + 6.5 O₂ = 4CO₂ + 5H₂O

Calculating the value of Δ H° rxn:

ΔH°rxn = ∑nH° f (products) - ∑nH° f (reactants)

Substituting the values we get,

Δ H° rxn = 4 (-393.5) + 5 (-241.8) - (-124.7)

= -1574 -1209 + 124.7

= -2783 - 124.7

= -2658.3 kJ/mol

Now, calculate the number of moles of butane in 8.30 gm.

Number of moles = mass/molar mass

= 8.30 / 58

= 0.143 moles

Thus, the total energy released in the reaction is,

Q = number of moles × ΔH° rxn

= 0.143 × (2658.3)

= 380.14 kJ

Hence, the total heat released in the reaction is 380.14 kJ.

6 0
2 years ago
When the elements in Group 1 are considered in order from top to bottom, each successive element at standard pressure has
kvasek [131]
When the element in group 1 are considered in order from top to bottom, each successive Elmer at standard pressure has a lower melting point and a lower boiling point.
7 0
2 years ago
draw the lewis structure for CO2, H2CO3, HCO3-, and CO3 2-.Rank these in order of increasing attraction to water molecules. Expl
gavmur [86]

Answer:

The structures are attached in file.

Hydrogen bonding and intermolecular forces is the reason for ranks allotted.

Explanation:

In determining Lewis structure, we calculate the overall number of valence electrons available for bonding.  Making carbon (the least electronegative atom) the central atom in the structure, we allocate valence electrons until each atom has achieved stability.

In order of decreasing affinity to water molecules:

CO_{3}^{2-}  > HCO_{3} ^{2-} > H_{2} CO_{3}

This is due to the fact that the CO_{3}^{2-}will accept protons more readily than the bicarbonate ion, HCO_{3} ^{2-}. Carbonic acid, H_{2} CO_{3} will not accept any more protons, hence it is the least attractive to water molecule, even though soluble.

3 0
2 years ago
Witch of the following isotopes would most likely be unstable and therefore radioactive?
STALIN [3.7K]
The answer is D; Mercury-194
All of the others are not when I looked them up

5 0
2 years ago
A chemical bond between two atoms results from a simultaneous
Elena L [17]
If you are asking for the word for this definition it is a <span>attraction by the two nucluei</span>
7 0
2 years ago
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