Answer:
E) 1, 2, and 3
Explanation:
50g H2O + 0.45g NaCl --> 50.45g saline solution
Answer:
Compressions are the parts where the coils are close together.
We have to calculate the molar mass of AL(OH)₃
Atomic mass (Al)=27 amu
Atomic mass (O)=16 amu
Atomic mass (H)=1 amu
molecular weight= 27 amu+3(16 amu + 1 amu) =78 amu.
Therefore, the molar mass of Al (OH)₃ is 78 g/ mol
Now, we calculate the number of moles in 98.3 g of aluminum hydroxide.
78 g-------------------1 mol
98.3 g----------------- x
x=(98.3 g * 1 mol) / 78 g=1.26 moles.
Answer: 1.26 moles.
I have a helpful trick for such problems.
Step 1:
Write the equation asked with exact moles given in question,
PCl₃ + Cl₂ → PCl₅ --------(1)
Step 2:
Write equations given in data along with energies,
P₄ + 6Cl₂ → 4PCl₃ Δ<span>H = −1280 kj -----(2)
</span>
P₄ + 10Cl₂ → 4PCl₅ ΔH<span> = −1774 kj -----(3)
Step 3:
Compare the equation 1 with eq 2 and 3 and modify eq 2 and 3 according to eq 1 both in terms of reactant and product and number of moles. For example in eq 1 PCl</span>₃ is on left hand side and its number of moles is one, so, modify eq, 2 according to eq 1 both in terms of moles and reactant product sides. i.e.
By inter converting eq 2, the sign of energy will change from negative to positive, and divide eq 2 with 4, to have its ratio's equal to eq 1
PCl₃ → 1/4 P₄ + 1.5 Cl₂ ΔH = +320 KJ
Same steps are done for eq 3, but in this case signs are not changed only moles are changed
1/4P₄ + 2.5Cl₂ → 1/4PCl₅ ΔH = −443.5 kj
Now,
Compare both last equations,
PCl₃ → 1/4 P₄ + 1.5 Cl₂ ΔH = +320 KJ
1/4P₄ + 2.5Cl₂ → 4/4PCl₅ ΔH = −443.5 kj
_____________________________________________
PCl₃ + Cl₂ → PCl₅ ΔH = -123.5 KJ
<span>Atoms vs. Ions. Atoms are neutral; they contain the same number of protons as electrons. By definition, an ion is an electrically charged particle produced by either removing electrons from a neutral atom to give a positive ion or adding electrons to a neutral atom to give a negative ion.</span>
