4. If you evaporate the water first, then the sand and salt will be nearly impossible to separate. That eliminates 1 and 2. You can't filter salt out from an aqueous solution, so that eliminates 3. 4 works because you can filter out the sand (which doesn't dissolve) then evaporate the water away from the salt.
Answer: " <span>1.8 * 10²⁴ molecules of O₂ " .
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3.0 moles O₂ * (6.02 * 10²³ molecules O₂ / 1 mol O₂) =
[ (3.0) *(6.02 * 10²³) ] molecules O₂
= 1.806 * 10²⁴ ; round to 2 significant figures.
= 1.8 * 10²⁴ molecules of O₂ .
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<h3>
Answer:</h3>
5.6 L
<h3>
Explanation:</h3>
We are given;
- Initial volume, V1 = 3.5 L
- Initial pressure, P1 = 0.8 atm
- Final pressure, P2 = 0.5 atm
We are required to calculate the final volume;
- According to Boyle's law, the volume of a fixed mass of a gas and the pressure are inversely proportional at a constant temperature.
- That is; P α 1/V
- Mathematically, P=k/V
- At two different pressure and volume;
P1V1 = P2V2
In this case;
Rearranging the formula;
V2 = P1V1 ÷ P2
= (0.8 atm × 3.5 L) ÷ 0.5 atm
= 5.6 L
Therefore, the resulting volume is 5.6 L
Answer: The bond formed between magnesium and oxygen is an ionic bond.
Explanation:
An ionic bond is formed when an atom transfer its valence electrons to another atom.
Whereas, a covalent bond is formed by the sharing of electrons between the atoms.
Silicon and oxygen forms silicon dioxide. Silicon has 4 valence electrons which are shared with each oxygen atom. Hence, silicon and oxygen forms a covalent bond.
Oxygen and oxygen shares two pairs of electrons therefore, a covalent bond is formed between oxygen and oxygen.
A covalent bond is formed between carbon and hydrogen as carbon has 4 valence electrons which are shared with four hydrogen atoms.
Magnesium has 2 valence electrons which are transferred to the oxygen atom in order to complete its octet.
Therefore, the bond formed between magnesium and oxygen is an ionic bond.
167 mL
P1V1 = P2V2
P1 = .8 atm
V1 = 250 mL
P2 = 1.2 atm
Solve for V2 —> V2 = P1V1/P2
V2 = (0.8 atm)(250 mL) / (1.2 atm) = 167 mL
