A gram is one million times larger than a microgram but one billion times smaller than a ______________

Calculate the number of grams of oxygen gas in a 24L container at STP

romanna [79]

There are 34 g of oxygen in the container.

We can use the Ideal Gas Law to solve this problem.

$pV = nRT$

But $n = \frac{m}{M}$ , so

$pV = \frac{m}{M}RT$ and

$m = \frac{pVM}{RT}\\$

STP is 0 °C and 1 bar, so

$m = \frac{\text{1 bar} \times \text{24 L} \times 32.00 \text{ g}\cdot\text{mol}^{-1}}{\text{0.083 14 } \text{bar}\cdot\text{L}\cdot\text{K}^{-1}\text{mol}^{-1}\times\text{273.15 K} } = \textbf{34 g}\\$

7 0

3 years ago

Please help, I'm confused and it's due very soon!

ryzh [129]

Answer:

1. Lanthanum-139 atom is the stable isotope of lanthanum with relative atomic mass 138.906348, 99.9 atom percent natural abundance and nuclear spin 7/2.

2. In fact, over 80% of electric cars sold globally utilized permanent magnet-based motors in 2019. These magnets are typically made with rare-earth materials such as neodymium and dysprosium, which have a very geographically constrained supply chain.

3. It is the second most reactive of the rare-earth metals after europium. Lanthanum oxidizes in air at room temperature to form La2O3. It slowly reacts with water and quickly dissolves in diluted acids, except hydrofluoric acid (HF) because of formation of a protective fluoride (LaF3) layer on the surface of the metal.

Explanation:

3 0

2 years ago

2.Which of the alcohols listed below would you expect to react most rapidly with PBr3?A)CH3CH2CH2CH2CH2CH2OHB)(CH3CH2)2CH(OH)CH2

Gnoma [55]

Answer:

A) CH3CH2CH2CH2CH2CH2OH

Explanation:

For this question, we have the following answer options:

A) CH3CH2CH2CH2CH2CH2OH

B) (CH3CH2)2CH(OH)CH2CH3

C) (CH3CH2)2CHOHCH3

D) (CH3CH2)3COH

E) (CH3CH2)2C(CH3)OH

We have to remember the reaction mechanism of the substitution reaction with $PBr_3$ . The idea is to generate a better leaving group in order to add a "Br" atom.

The $PBr_3$ attacks the "OH" generation new a bond to P (O-P bonds are very strong), due to this new bond we will have a better leaving group that can remove the oxygen an allow the attack of the Br atom to generating a new C-Br bond. This is made by an Sn2 reaction. Therefore we will have a faster reaction with primary substrates. In this case, the only primary substrate is molecule A. So, "CH3CH2CH2CH2CH2CH2OH" will react faster.

See figure 1

I hope it helps!