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Calculate: Punnett squares can be used to predict probable outcomes of genetic crosses. To calculate probability, divide the number of one kind of possible outcome by the total number of all possible outcomes. For example, if you toss a coin, the chance it will land on heads is equal to 1 ÷ 2.
Answer:
D. 44.2 g O₂
General Formulas and Concepts:
<u>Gas Laws</u>
- STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at <em>1 atm, 273 K</em>
<u>Stoichiometry</u>
- Dimensional Analysis
- Mole Ratio
Explanation:
<u>Step 1: Define</u>
<em>Identify given.</em>
61.9 L O₂ at STP
<u>Step 2: Convert</u>
We know that the oxygen gas is at STP. Therefore, we can set up and solve for how many <em>moles</em> of O₂ is present:
Recall the Periodic Table (Refer to attachments). Oxygen's atomic mass is roughly 16.00 grams per mole (g/mol). We can use a mole ratio to convert from <em>moles</em> to <em>grams</em>:
Now we deal with sig figs. From the original problem, we are given 3 significant figures. Round your answer to the <u>exact</u> same number of sig figs:
∴ our answer is letter choice D.
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Topic: AP Chemistry
Unit: Stoichiometry
Ammonium iodide, or NH₄I, is a salt. Since all salts are strong electrolytes, when ammonium iodide is dissolved in water, it would dissociate into ammonium ions and iodide ions. Hence, the major species present would be: <em>NH₄⁺ and I⁻ ions</em>.
Answer:
B. CH3CH2OH
Explanation:
Ethanol has a chemical formula of CH3CH2OH, it is the second member of the series in the alkanol family. Ethanol is a colourless, volatile liquid with a characteristic smell and taste. It is readily soluble in water in all proportions. It has a boiling point of 78° C. The physical properties such as the solubility of alkanols are affected by the presence of hydrogen bonding. The hydroxyl group is capable of bonding to other alkanol molecules. The boiling points rise with increasing molecular mass.
Hydrogen bonding helps the molecules to stick together. For example comparing the boiling point of pentane ( 36° C) with that of butan-1-ol (118° C) , the boiling point of alkanol is much higher even though the two compound are of similar relative molecular mass. This is due to the presence of hydrogen bonds in butanol.
Hydrocarbons are not soluble in water but alkanols are soluble in water because of the hydroxyl groups in the molecules can form hydrogen bond with water. Solubility of alkanol in water decreases as the number of carbon atom increases. Primary alcohol with more than five carbon atoms are insoluble in water.
<span>I don't know if my expression is right but: 25g NH3 x 1 mol/17.04g NH3 x 6.022x10^23 molecules NH3/mol NH3.</span>