Which liquid would be the most difficult to raise or lower the temperature of

Determine the mass in grams of 3.75 x 10^21 atoms of zinc. (the mass of one mole of zinc is 65.39 g)

Nastasia [14]

Answer: The mass in $3.75 \times 10^{21}$ atoms of zinc is 0.405 g.

Explanation:

Given: Atoms of zinc = $3.75 \times 10^{21}$

It is known that 1 mole of every substance contains $6.022 \times 10^{23}$ atoms. So, the number of moles in given number of atoms is as follows.

$Moles = \frac{3.75 \times 10^{21}}{6.022 \times 10^{23}}\\= 0.622 \times 10^{-2}\\= 0.0062 mol$

As moles is the mass of a substance divided by its molar mass. So, mass of zinc (molar mass = 65.39 g/mol) is calculated as follows.

$Moles = \frac{mass}{molar mass}\\0.0062 mol = \frac{mass}{65.39 g}\\mass = 0.405 g$

Thus, we can conclude that the mass in $3.75 \times 10^{21}$ atoms of zinc is 0.405 g.

6 0

3 years ago

The following data were collected for the rate of disappearance of NO in the reaction 2NO(g)+O2(g)→2NO2(g)::

Anit [1.1K]

Answer:

a) The rate law is: v = k[NO]² [O₂]

b) The units are: M⁻² s⁻¹

c) The average value of the constant is: 7.11 x 10³ M⁻² s⁻¹

d) The rate of disappearance of NO is 0.8 M/s

e) The rate of disappearance of O₂ is 0.4 M/s

Explanation:

The experimental rates obtained can be expressed as follows:

v1 = k ([NO]₁)ᵃ ([O₂]₁)ᵇ = 1.41 x 10⁻² M/s

v2 = k ([NO]₂)ᵃ ([O₂]₂)ᵇ = 5.64 x 10⁻² M/s

v3 = k ([NO]₃)ᵃ ([O₂]₃)ᵇ = 1.13 x 10⁻¹ M/s

where:

k = rate constant

[NO]₁ = concentration of NO in experiment 1

[NO]₂ = concentration of NO in experiment 2

[NO]₃ = concentration of NO in experiment 3

[O₂]₁ = concentration of O₂ in experiment 1

[O₂]₂ = concentration of O₂ in experiment 2

[O₂]₃ = concentration of O₂ in experiment 3

a and b = order of the reaction for each reactive respectively.

We can see these equivalences:

[NO]₂ = 2[NO]₁

[O₂]₂ = [O₂]₁

[NO]₃ = [NO]₂

[O₂]₃ = 2[O₂]₂

So, v2 can be written in terms of the concentrations used in experiment 1 replacing [NO]₂ for 2[NO]₁ and [O₂]₂ by [O₂]₁ :

v2 = k (2 [NO]₁)ᵃ ([O₂]₁)ᵇ

If we rationalize v2/v1, we will have:

v2/v1 = k *2ᵃ * ([NO]₁)ᵃ * ([O₂]₁)ᵇ / k * ([NO]₁)ᵃ * ([O₂]₁)ᵇ (the exponent "a" has been distributed)

v2/v1 = 2ᵃ

ln(v2/v1) = a ln2

ln(v2/v1) / ln 2 = a

a = 2

(Please review the logarithmic properties if neccesary)

In the same way, we can find b using the data from experiment 2 and 3 and writting v3 in terms of the concentrations used in experiment 2:

v3/v2 = k ([NO]₂)² * 2ᵇ * ([O₂]₁)ᵇ / k * ([NO]₂)² * ([O₂]₂)ᵇ

v3/v2 = 2ᵇ

ln(v3/v2) = b ln 2

ln(v3/v2) / ln 2 = b

b = 1

Then, the rate law for the reaction is:

v = k[NO]² [O₂]

Since the unit of v is M/s and the product of the concentrations will give a unit of M³, the units of k are:

M/s = k * M³

M/s * M⁻³ = k

M⁻² s⁻¹ = k

To obtain the value of k, we can solve this equation for every experiment:

k = v / [NO]² [O₂]

for experiment 1:

k = 1.41 x 10⁻² M/s / (0.0126 M)² * 0.0125 M = 7.11 x 10³ M⁻² s⁻¹

for experiment 2:

k = 7.11 x 10³ M⁻² s⁻¹

for experiment 3:

k = 7.12 x 10³ M⁻² s⁻¹

The average value of k is then:

(7.11 + 7.11 + 7.12) x 10³ M⁻² s⁻¹ / 3 = 7.11 x 10³ M⁻² s⁻¹

The rate of the reaction when [NO] = 0.0750 M and [O2] =0.0100 M is:

v = k [NO]² [O₂]

The rate of the reaction in terms of the disappearance of NO can be written this way:

v = 1/2(Δ [NO] / Δt) (it is divided by 2 because of the stoichiometric coefficient of NO)

where (Δ [NO] / Δt) is the rate of disappearance of NO.

Then, calculating v with the data provided by the problem:

v = 7.11 x 10³ M⁻² s⁻¹ * (0.0750M)² * 0.0100M = 0.4 M/s

Then, the rate of disappearance of NO will be:

2v = Δ [NO] / Δt = 0.8 M/s

The rate of disappearance of O₂ has to be half the rate of disappearance of NO because two moles of NO react with one of O₂. Then Δ [O₂] / Δt = 0.4 M/s

With calculations:

v = Δ [O₂] / Δt = 0.4 M/s (since the stoichiometric coefficient is 1, the rate of disappearance of O₂ equals the rate of the reaction).

3 0

3 years ago

Which nonmetal would an ion of Ca2+ MOST LIKELY ionically bond with in a 1:1 ratio? A) one atom of neon B) one atom of carbon C)

GalinKa [24]

Ca2+ would bond to any element in a 1 to 1 ratio that had an equal and opposite charge.

Neon is a noble gas, and doesn’t form bonds m

Carbon isn’t typically found in ion state, but if it did, it would likely by C4+

Flouring in ionic state is F1-, so you would need 2 flourines to cancel the 2+ charge of Calcium

Then the only option left would be Oxygen which, when in ion form is found be 2-

5 0

3 years ago

Read 2 more answers

PLS heLPPP. IM DYINGG

Shkiper50 [21]

Answer:

exothermic

Explanation:

This chemical reaction is an exothermic reaction because heat is liberated into the environment.

In organic chemistry, the reaction is termed a combustion reaction. In such a reaction, a fuel combines with oxygen to produce carbon dioxide and water.

It is an energy transformation from chemical energy to heat energy.

An exothermic reaction is one in which heat is liberated to the surrounding.
The surrounding becomes hotter at the end of the reaction.

In the reaction depicted, heat is liberated.

4 0

3 years ago

A student calculated the standard enthalpy change of formation of ethane C2H6 using a method based on standard enthalpy change o

Tom [10]

C2H6 + 302 -------> 2C + 3H20

8 0

3 years ago