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4 years ago

How do the atomic number and the

Chemistry

1 answer:

Tomtit [17]4 years ago

4 0

Answer:

It's the first option.

Explanation:

The atomic number tells us the number of protons in the nucleus of an atom.

It is the number which identifies an atom.

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The bromination of acetone is acid-catalyzed.CH3COCH3 + Br2 CH3COCH2Br + H+ + Br -The rate of disappearance of bromine was measu

Ann [662]

Answer:

a) The rate law is:

rate = k[Acetone][Br₂]⁰[H⁺] = k[Acetone][H⁺]

b) The value of k is:

k = 3.86 × 10⁻³ M⁻¹ · s⁻¹

Explanation:

Acetone (M) Br2 (M) H+ (M) Rate (M/s)

0.30 0.050 0.050 5.7 x 10-5

0.30 0.10 0.050 5.7 x 10-5

0.30 0.050 0.10 1.2 x 10-4

0.40 0.050 0.20 3.1 x 10-4

0.40 0.050 0.050 7.6 x 10-5

A generic rate law for this reaction could be written as follows:

rate = k[Acetone]ᵃ[Br₂]ᵇ[H⁺]ⁿ

The rate for the reaction in trial 2 is:

rate 2 = 5.7 ×10⁻⁵M/s = k(0.3)ᵃ(0.1)ᵇ(0.050)ⁿ

For the reaction in trial 1:

rate 1 = 5.7 ×10⁻⁵M/s = k(0.3)ᵃ(0.050)ᵇ(0.050)ⁿ

If we divide both expressions, we can obtain "b": rate2 / rate1:

rate2/rate1 = k(0.3)ᵃ(0.1)ᵇ(0.050)ⁿ / k(0.3)ᵃ(0.050)ᵇ(0.050)ⁿ

1 = 2ᵇ

b = 0

If we now take the expressions from trial 3 and 1 and divide them, we can obtain "n":

rate 3/rate 1 = k(0.3)ᵃ(0.050)⁰(0.01)ⁿ/ k(0.3)ᵃ(0.050)⁰(0.050)ⁿ

2.1 = 2ⁿ Applying ln to both side of the equation:

ln 2.1 = n ln2

ln2.1/ln2 = n

1 ≅ n

Taking now the reaction in trial 5 and 1 and dividing them:

rate 5/rate 1 = k(0.4)ᵃ(0.050)⁰(0.050) / k(0.3)ᵃ(0.050)⁰(0.050)

4/3 = 4/3ᵃ

a = 1

a)Then the rate law can be written as follows:

rate = k[Acetone][Br₂]⁰[H⁺]

It might be suprising that the rate of bromination of acetone does not depend on the concentration of Br₂. However, looking at the reaction mechanism, you can find out why.

b) Now, we can find the constant k for every experiment and calculate its average value:

rate / [Acetone][Br₂]⁰[H⁺] = k

For reaction 1:

k1 = 5.7 ×10⁻⁵M/s / (0.3 M)(0.050 M) = 3.8 ×10⁻³ M⁻¹ · s⁻¹

Reaction 2: k2 = 5.7 ×10⁻⁵M/s / (0.30 M)(0.050 M) = 3.8 ×10⁻³ M⁻¹ · s⁻¹

Reaction 3: k3 = 1.2 ×10⁻⁴M/s / (0.30 M)(0.10 M) = 4.0 ×10⁻³ M⁻¹ · s⁻¹

Reaction 4: k4 = 3.1 ×10⁻⁴M/s / (0.40 M)(0.20 M) = 3.9 ×10⁻³ M⁻¹ · s⁻¹

Reaction 5: k5 = 7.6 ×10⁻⁵M/s / (0.4 M)(0.05 M) = 3.8 ×10⁻³ M⁻¹ · s⁻¹

Averge value of k:

k = (k1 + k2 + k3 + k4 + k5)/5 = 3.86 × 10⁻³ M⁻¹ · s⁻¹

3 0

3 years ago

When lithium nitride, Li 3 N ( s ) , is treated with water, H 2 O ( l ) , ammonia, NH 3 ( g ) , is produced. Predict the formula

allochka39001 [22]

Answer : The formula of the gas produced is, $PH_3$ (phosphine gas)

Explanation :

According to the question, when sodium phosphide is treated with water then it react to give phosphine gas and sodium hydroxide.

The balanced chemical reaction will be:

$Na_3P(aq)+3H_2O(l)\rightarrow PH_3(g)+3NaOH(aq)$

By Stoichiometry of the reaction we can say that:

1 mole of sodium phosphide reacts with 3 moles of water to give 1 mole of phosphine gas and 3 moles of sodium hydroxide.

Thus, the formula of the gas produced is, $PH_3$ (phosphine gas)

8 0

3 years ago

CH,O<br> Needed:<br> Available:<br> Shared:<br> Bonds:

Alona [7]

Answer:

hy do C-C bonds and C-H bonds have high potential energy levels? ... electronegativity so the electrons in the covalent bond are equally shared. Term. Which functional groups are commonly found on a carbohydrate? ... few organisms have the specific enzymes needed to break the bond in the B-form ...

Explanation:

3 0

3 years ago

Enter the formula for the compound cobalt(II) phosphate. Express your answer as a chemical formula.

alexira [117]

Answer:

$Co_3(PO_4)_2$

Explanation:

Naming of the ionic compounds:-

The name of the cation is written first and the the name of the anion is written after the name of the cation separated by single space.
The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
In case of transition metals, the oxidation state are written in roman numerals in bracket in front of positive ions.

Hence, given ionic compound:-

Cobalt(II) phosphate

So, Cobalt will have a positive charge of +2

Phosphate is $PO_4^{3-}$

So, the formula is :-

Co $PO_4^{3-}$

2 3

$Co_3(PO_4)_2$

5 0

3 years ago

How many neutrons are in a Cs-130 isotope?

den301095 [7]

It has 78 neutrons in a cesium

5 0

3 years ago