Answer:a) ∆E=-0.077KJ (exothermic)
b) ∆E = 110KJ (endothermic)
Explanation:
a) ∆E = q + w
q= 0.763 KJ
w= -840J = -0.840 KJ
∆E = 0.763-0.840 = - 0.077KJ
Exothermic reaction are those reactions that proceeds with the release of heat to the surroundings and Energy is negative in exothermic processes.
b)/∆E = q+w
q= 66.1KJ, w=44KJ
∆E = 101KJ
And it is endothermic
When work is done on a system, the international energy increases.
Answer:
It depends what other values you have. Can you give more info? If they give density then you can solve for m.
Answer:
Explanation:
You need the conversion factor to convert the value of 12.33 kPa to milimiters of mercury, mmHg.
The converstion factors are looked at tables, which today you can find in internet.
Since the conversions between kPa and atm and between atm and mmHg are more widely known, I will show the conversion using those relations:
⇒ 101.325 kPa = 760 mmHg
Then, dividing both sides by 101.325 kPa you get the conversion factor:
- 1 = 760 mmHg / 101.325 kPa
Now, multiply 12.33 kPa by that conversion factor:
- 12.33 kPa × 760 mmHg / 101.325 kPa = 92.48 mmHg ← answer
The empirical formula is C₇H₆O₂.
Assume that you have 100 g of the compound.
Then you have 68.84 g C and 4.962 g H.
Mass of O = (100 – 68.84 – 4.962) g = 26.20 g O.
Now, we must convert these masses to moles and find their ratios.
From here on, I like to summarize the calculations in a table.
<u>Element</u> <u>Mass/g</u> <u>Moles</u> <u>Ratio</u> <u> ×2</u> <u>Integers</u>
C 68.84 5.732 3.501 7.001 7
H 4.962 4.923 3.006 6.012 6
O 26.20 1.638 1 2 2
The empirical formula is C₇H₆O₂.
Answer:
- Option <u><em>d) isotope</em></u>.
Explanation:
All atoms of a same element have equal number of protons (atomic number) but <em>may</em> <em>differ in the number of neutrons.</em>
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The atoms that differ in the number of neutrons are named<em> isotopes</em>.
For example: carbon-12 and carbon-13 are diferent isotopes of the same element, carbon. They have the same number of protons (6, which is the atomic number of carbon). On the other hand, while carbon-12 has 6 neutrons, carbon-13 has 7 neutrons.
As per the other choices:
- a) <em>anions</em> are ions with negative charges: atoms (or group of atoms) that have gained one or more electrons.
- b) <em>cations</em> are ions with positive charge: atoms (or group of atoms) that have lost one or more electrons.
- e) <em>atoms</em> are the individual minimum parts of an element that preserves the properties of such element. All atoms of the same element have the same number of protons and have, essentially, the same chemical properties.