Smaller the atomic size get smaller as it goes across a period. This is because periods all have the same amount of valence electron shell numbers (like period 2 has 2 valance shells around the atom) but at the same exact time, the number of protons increase going down the period. This means there’s more/a stronger pull from the protons to the outer balance electrons making the valance electron layers pull inward more, but on the next layer of new balance electron shell is formed so the distance between the outer most balanced electron in the protons is wider than the previous level, but like before the gap decreases as a you go down the period. Hope this makes sense
Answer:
15.3 g
Explanation:
- Fe₂O₃ (s) + 2Al (s) → 3Fe (l) + Al₂O₃ (s)
First we convert 8.0 grams of aluminum into moles, using its molar mass:
- 8.0 g Al ÷ 27 g/mol = 0.30 mol Al
Then we <u>convert 0.30 moles of aluminum into moles of aluminum oxide</u>, using the<em> stoichiometric coefficients</em>:
- 0.30 mol Al * = 0.15 mol Al₂O₃
Finally we convert 0.15 moles of Al₂O₃ into grams, using its molar mass:
- 0.15 mol Al₂O₃ * 102 g/mol = 15.3 g Al₂O₃
Answer: The kinetic theory of matter states that all matter is made of small particles that are in random motion and that have space between them. And since gases have even more energy than liquids, their particles are moving around a lot more, too.
Explanation:
Answer:I think c or b but mostly b
Explanation:
Question:
Zinc metal is added to hydrochloric acid to generate hydrogen gas and is collected over a liquid whose vapor pressure is the same as pure water at 20.0 degrees C (18 torr). The volume of the mixture is 1.7 L and its total pressure is 0.987 atm. Determine the number of moles of hydrogen gas present in the sample.
A. 0.272 mol
B. 0.04 mol
C. 0.997 mol
D. 0.139 mol
E. 0.0681 mol
Answer:
The correct option is;
E. 0.0681 mol
Explanation:
The equation for the reaction is
Zn + HCl = H₂ + ZnCl₂
Vapor pressure of the liquid = 18 torr = 2399.803 Pa
Total pressure of gas mixture H₂ + liquid vapor = 0.987 atm
= 100007.775 Pa
Therefore, by Avogadro's law, pressure of the hydrogen gas is given by the following equation
Pressure of H₂ = 100007.775 Pa - 2399.803 Pa = 97607.972 Pa
Volume of H₂ = 1.7 L = 0.0017 m³
Temperature = 20 °C = 293.15 K
Therefore,
Therefore, the number of moles of hydrogen gas present in the sample is n ≈ 0.0681 moles.