1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
I am Lyosha [343]
3 years ago
14

A sample of the compound magnesium oxide is synthesized as follows. 60. g of magnesium is burned and produces 100. g of magnesiu

m oxide, indicating that the magnesium combined with 40. g of oxygen in the air. If 30. g of magnesium had been used, what mass of oxygen would have combined with it? What law of chemistry is used in solving this problem?
Chemistry
1 answer:
Inga [223]3 years ago
5 0

Answer:

30 g of magnesium would be combined with 20 g of oxygen. The law used solving this problem is the Lavoisier Law of conservation of mass.

Explanation:

If 60 g of magnesium combines with 40 g of oxygen to make 100 g of magnesium oxide, then 30 g of magnesium will combine with 20 g of oxygen to make 50 g of magnesium oxide.

This happens because in a chemical reaction there is no creation or descruction of atoms, only a rearrangement. Therefore, the mass of reactants should be equal to the mass of products.

The following equation represents the proportions of the substances:

Mg + 1/2O₂ → MgO

You might be interested in
HNO3 + KOH → ____ + _____
natita [175]

Answer:

HNO3 + KOH → _KNO3___ + __H2O___

Explanation:

It's balanced

hope it helps

7 0
3 years ago
what is weather? What are some terms we use to describe weather? What affects the weather in a particular place over time?
leva [86]
Weather is the temperature or climate over a short period of time.
8 0
3 years ago
Read 2 more answers
The decomposition reaction of N2O5 in carbon tetrachloride is 2N2O5−→−4NO2+O2. The rate law is first order in N2O5. At 64 °C the
Mademuasel [1]

Answer:

(a) rate =  4.82 x 10⁻³s⁻¹  [N2O5]

(b) rate =   1.16 x 10⁻⁴  M/s

(c) rate =   2.32 x 10⁻⁴ M/s

(d) rate =   5.80 x 10⁻⁵ M/s

Explanation:  

We are told the rate law is first order in N₂O₅, and its rate constant is 4.82 x 10⁻³s⁻¹ . This means the rate is proportional to the molar concentration   of   N₂O₅, so

(a) rate = k [N2O5] = 4.82 x 10⁻³s⁻¹ x [N2O5]

(b) rate = 4.82×10⁻³s⁻¹  x 0.0240 M =  1.16 x 10⁻⁴ M/s

(c) Since the reaction is first order if the concentration of  N₂O₅ is double the rate will double too:  2 x   1.16 x 10⁻⁴ M/s = 2.32 x 10⁻⁴ M/s

(d) Again since the reaction is halved to 0.0120 M, the rate will be halved to

1.16 x 10⁻⁴ M/s / 2 =  5.80 x 10⁻⁵ M/s

3 0
3 years ago
Read 2 more answers
For the reaction: CH3NH2(aq) + H2O(aq) ⇌ CH3NH3 +(aq) + OH- Determine the change in the pH (ΔpH) for the addition of 6.7 M CH3NH
Korolek [52]

Answer:

The change in the pH (ΔpH) is 2,17

Explanation:

The reaction:

CH₃NH₂(aq) + H₂O(aq) ⇌ CH₃NH₃⁺(aq) + OH⁻

kb = \frac{[OH^{-}][CH_{3}NH_{3}^+]}{[CH_{3}NH_{2}]} <em>(1)</em>

In equilibrium, a solution of CH₃NH₂ 4,7M produces:

[CH₃NH₂] = 4,7 - x

[CH₃NH₃⁺] = x

[OH⁻] = x

Replacing in (1):

4,38x10^{-4} = \frac{x^2}{4,7-x}

x² + 4,38x10⁻⁴x - 2,0586x10⁻³ = 0

The solutions are:

x = -0,0456 No physical sense. There are not negative concentrations.

x = 0,04515 Real answer.

The concentration of [OH⁻] is 0,04515 M.

As pOH = -log [OH⁻] And pH+pOH = 14. The pH of this solution is:

<em>pH = 12,65</em>

The addition of 6,7M produce this changes in concentrations:

[CH₃NH₂] = 4,656 + x

[CH₃NH₃⁺] = 6,74515 - x

[OH⁻] = 0,04515 - x

Replacing in (1) you will obtain:

x² - 6,7907x + 0,3025 = 0

Solving for x:

x = 6,74586 No physical sense

x = 0,04484 Real answer.

Thus, [OH⁻] = 0,04515 - 0,044842 = 3,08x10⁻⁴M

pOH = 3,51.

<em>pH = 10,49</em>

Thus ΔpH is 12,65 - 10,49 = <em>2,16 ≈ 2,17</em>

I hope it helps!

4 0
3 years ago
What would be another property that we Earthlings could use to classify stars?
Blizzard [7]

Answer: At the point when space experts take a gander at an article's range, they can decide its arrangement dependent on these frequencies. The most well-known technique stargazers use to decide the sythesis of stars, planets, and different articles is spectroscopy. This spread-out light is known as a range.

Explanation:

8 0
3 years ago
Other questions:
  • The outer planets are very large making up 99 percent of the mass of the bodies orbiting the Sun.
    6·2 answers
  • Explain why are metals good conductors and why covalent bonds are not
    8·1 answer
  • Apply the Law of Conservation of Mass to the following problem: During a combustion reaction, 12.2 grams of methane reacts with
    13·1 answer
  • Blast furnaces extract pure iron from the iron(III) oxide in iron ore in a two step sequence.In the first step, carbon and oxyge
    15·1 answer
  • Which of the following choices tells a computer how to preform a certain task?
    10·1 answer
  • PLEASEE HELPP ME WITH THIS QUESTIONN!!!!!1
    6·1 answer
  • `In this lesson we discussed how to abbreviate electron configurations using what is called noble gas configuration. So if you w
    7·1 answer
  • Write down the names of compounds represented by the following formulae:
    8·1 answer
  • What job uses % vol units?
    7·2 answers
  • Sodium bicarbonate =sodium carbonate + water + carbon dioxide gas
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!