The boiling point of liquid nitrogen is 77 kelvin. It is observed that ice forms at the opening of a container of liquid nitroge
1 answer:
Answer:
The answer is "The First choice".
Explanation:
The whole question can be found in the file attached.
The water vapor inside the air freezes thru the entrance of its nitrogen. This is because liquid nitrogen has a very low temperature and seems to be sufficiently cold to condensed and freeze the steam of water. At air pressure, it has a boiling temperature of -196°C. Freezing the skin producing freeze or cold burns can be associated with direct contact.
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Answer:
Explanation:
We are asked to find how many atoms are in 8.88 grams of silicon.
<h3>1. Grams to Moles </h3>First, we convert grams to moles. We use the molar mass or the mass of 1 mole of a substance. These values are found on the Periodic Table as they are equal to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up silicon's molar mass.
- Si: 28.085 g/mol
We will convert using dimensional analysis. Set up a conversion factor with the molar mass.
We are converting 8.88 grams of silicon to moles, so we multiply by this value.
Flip the fraction so the units of grams of silicon cancel.
Next, we convert moles to atoms. We use Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of silicon.
Set up another conversion factor.
Multiply by the number of moles we calculated.
The units of moles of silicon cancel.
The original measurement of 8.88 grams has 3 significant figures, so our answer must have the same.
For the number we calculated, that is the hundredth place. The 4 in the thousandth place tells us to leave the 0 in the hundredth place.
<u>8.88 grams of silicon contains 1.90 ×10²³ atoms of silicon.</u>
In reaction 1 of the Krebs cycle, acetyl‑CoA formed in the pyruvate dehydrogenase reaction condenses with the four‑carbon compound to form <em>citrate </em>with the elimination of coenzyme A. Since the product has three carboxyl groups, this pathway is referred to as the cycle. In reaction 2 of the Krebs cycle, this product then undergoes to form<em> isocitrate. </em>The enzyme is called aconitase because the compound cis‑aconitate is the <em>intermediate product</em> of the reaction. Reaction 3 eliminates CO2 to form the five‑carbon dicarboxylic acid <em>α-cetoglutarate. </em>Oxidation also occurs, with electrons transferred from the substrate to <em>COO-</em> . Consequently, this reaction is an oxidative decarboxylation.
In the image, you can see the reaction 2 in Krebs cycle is a two steps reaction with an intermediate cis-aconitase and a product called isocitrate.
