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MissTica
2 years ago
13

5. What is the mole fraction of NaOH in an aqueous solution that contains 31.0 % NaOH by mass?

Chemistry
1 answer:
Liono4ka [1.6K]2 years ago
6 0

Answer:

16.8%      

Explanation:

31% NaOH    molar mass  40 gm

69% H2O      molar mass  18  gm

1000 gm would be  

 310 gm NaOH  or  310/40 = 7.75 moles

 690 gm of H2O or  690/18 = 38.333 moles

7.75 / (7.75 + 38.333) = .168   mole fraction

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Which notation represents the largest atomic radius?
Darina [25.2K]

Answer:

Calcium(Ca)

Explanation:

  • Atomic radius is the distance from the nucleus of an atom the outermost energy shell or energy level.
  • The atomic radii of metals are greater than the ionic radii since metals form ions by losing electrons.
  • Calcium atom has a larger atomic radius compared to magnesium atom because it has more energy levels. Calcium atoms have four energy levels while magnesium atoms have three energy levels.
7 0
3 years ago
Non-conjugated β, γ-unsaturated ketones, such as 3-cyclohexenone, as in base-catalyzed equilibrium with their α,β-unsaturated is
uranmaximum [27]

Answer:

See the attached file for the structure.

Explanation:

Find attached for the explanation

7 0
3 years ago
How much heat in kj is released by burning 9.5 grams of methane?
tatyana61 [14]
Methane is the compound CH4, and burning it uses the reaction:

CH4 + O2 -> CO2 + H2O, which is rather exothermic. To find the heat released by burning a certain amount of the substance, you should look at the bond enthalpy of each compound, and then compare the values before and after the reaction. In methane, there are 4 C-H bonds, which have bond energy of 416 kj/mol, resulting in a total bond energy of 1664 kj/mol. O2 is 494 kj/mol. Therefore we have a total of 2080 kj/mol on the left side. On the right side we have CO2, which has 2 C=O bonds, each at 799 kj/mol each, resulting in 1598 kj/mol, and H2O has 2 O-H bonds, at 459kj/mol each, resulting in a total of 2516 kj/mol on the right hand side. Now, this may be confusing because the left hand side seems to have less heat than the right, but you just need to remember: making minus breaking, which results in a total change of 436kj/mol heat evolved.

Now it is a simple matter of find the mols of CH4 reacted, using n=m/mr.

n = 9.5/16.042 = 0.592195 mol

Therefore, if we reacted 0.592195 mol, and we produced 436 kj for one mol, the total amount of energy evolved was 436*<span>0.592195 kj, or 258.197 kj.</span>
7 0
3 years ago
9. For each reaction listed, identify the proton donor (or acid) and the proton acceptor(or base).
Talja [164]

Answer:

Explanation:

conjugate acid, based on Brønsted–Lowry acid–base theory, is a chemical compound that is formed by the reception of a proton by a base

a. CH₃COOH + H₂O ⇌ H₃0⁺ + CH₃C00-

Acid <> CH₃COOH

Base <> H₂O

Conjugate acid <> H₃0 +

Conjugate base <>CH₃C00-

b. HCO₃ + H₂O ⇌ H₂CO₃⁻ + OH⁻

Acid <> H₂O

Base <> HCO₃

Conjugate acid <> H₂CO₃⁻

Conjugate base <>OH⁻

C. HNO₃ + SO₄²⁻ ⇌ HSO₄⁻ + NO₃⁻

Acid <>HNO₃

Base <>SO₄²⁻

Conjugate acid <>HSO₄⁻

Conjugate base <>NO₃⁻

A Bronsted acid is reffered to as a proton donor while a Bronsted base is a proton acceptor

3 0
3 years ago
A chemistry student measures out 41 grams of sodium hydroxide, NaOH. They react it with an excess of hydrochloric acid, HCl, for
exis [7]
The answer will be around 687.928 grams
8 0
3 years ago
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