0.50 moles of oxygen gas will react.
Balanced chemical eqation for reaction of calcium with oxygen:
2Ca + O₂ → 2CaO
n(Ca) = 1.0 mol; amount of calcium
From balanced chemical reaction, we can see that 2 moles of calcium reacts with one mole of oxygen gas. Ratio of moles is 2 : 1.
n(Ca) : n(O₂) = 2 : 1; ratio of the amount of substance of calcium and oxygen gas
n(O₂) = n(Ca) / 2; two times less amount of oxygen than calcium
n(O₂) = 1.0 mol / 2
n(O₂) = 0.5 mol; amount of oxygen gas needed for this chemical reaction.
More about stoichiometry: brainly.com/question/16060223
#SPJ4
At the core of the sun, it can be more than 27 million degrees Fahrenheit (15 million degrees Celsius).
From the core, energy moves to the radiative zone, where it bounces around for up to 1 million years before moving up to the convective zone, the upper layer of the sun's interior. The temperature here drops below 3.5 million degrees F (2 million degrees C). Large bubbles of hot plasma form a soup of ionized atoms and move upwards to the photosphere.
<http://www.space.com/17137-how-hot-is-the-sun.html>
Answer:
Mass percent N₂ = 89%
Mass percent H₂ = 11%
Explanation:
First we <u>use PV=nRT to calculate n</u>, which is the total number of moles of nitrogen and hydrogen:
- 1.03 atm * 7.45 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 305 K
So now we know that
- MolH₂ + MolN₂ = 0.307 mol
and
- MolH₂ * 2 g/mol + MolN₂ * 28 g/mol = 3.49 g
So we have a <u>system of two equations and two unknowns</u>. We use algebra to solve it:
Express MolH₂ in terms of MolN₂:
- MolH₂ + MolN₂ = 0.307 mol
Replace that value in the second equation:
- MolH₂ * 2 g/mol + MolN₂ * 28 g/mol = 3.49
- (0.307-MolN₂) * 2 + MolN₂ * 28 = 3.49
- 0.614 - 2MolN₂ + 28molN₂ = 3.49
Now we calculate MolH₂:
- MolH₂ + MolN₂ = 0.307 mol
Finally, we convert each of those mol numbers to mass, to <u>calculate the mass percent</u>:
- N₂ ⇒ 0.111 mol * 28 g/mol = 3.108 g N₂
- H₂ ⇒ 0.196 mol * 2 g/mol = 0.392 g H₂
Mass % N₂ = 3.108/3.49 * 100% = 89.05% ≅ 89%
Mass % H₂ = 0.392/3.49 * 100% = 11.15% ≅ 11%
a. Group 2
b. Metal
a. The current highest numbered element known is Oganesson with an atomic number of 118 and it's the last period 7 element in group 18 (Noble gases). The hypothetical element number 120, would be the 2nd element in period 8 and the described electron configuration matches other group 2 elements such as Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium.
b. The hypothetical element would be quite similar to the other group 2 elements which are the alkaline earth metals. The element would be expected to be a bit more reactive than Radium.
Answer:
a have stripped pattern
Explanation:
did it on edunuity and studied on quizlet