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3 years ago

How many moles of atoms oxygen are in 4.92x10^24 molecules of KNO2?

Chemistry

1 answer:

Nana76 [90]3 years ago

8 0

Answer:

8.17

Explanation:

from

N=n×La

n=N/La

n=4.92×10^24/6.022×10^23

n= 8.17 moles

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At a certain temperature the rate of this reaction is first order in HI with a rate constant of :0.0632s2HIg=H2g+I2g Suppose a v

olya-2409 [2.1K]

Answer:

$\boxed{\text{28.0 s}}$

Explanation:

Whenever a question asks you, "How long does it take to reach a certain concentration?" or something like that, you must use the appropriate integrated rate law expression.

The integrated rate law for a first-order reaction is

$\ln \left (\dfrac{[A]_{0}}{[A]} \right ) = kt$

Data:

[A]₀ = 1.28 mol·L⁻¹

[A] = 0.17 [A]₀

k = 0.0632 s⁻¹

Calculation:

$\begin{array}{rcl}\ln \left (\dfrac{[A]_{0}}{0.170[A]_{0}} \right ) & = & 0.0632t\\\\\ln \left (5.882) & = & 0.0632t\\1.772 & = & 0.0632t\\\\t & = & \dfrac{1.772}{0.0632}\\\\t & = & \textbf{{28.0 s}}\\\end{array}\\\text{It will take } \boxed{\textbf{28.0 s}} \text{ for [HI] to decrease to 17.0 \% of its original value.}$

8 0

3 years ago

Which of the examples below is a chemical agent? Select one:

Sergeu [11.5K]

Chlorine, Anthax is a biological agent, and uranium is a radioactive agent, and dynamite is just a no. Chlorine is a chemical gas.

6 0

3 years ago

Determine the mass of 2.5 cups of water if the density of water is 1.00 g/cm3 and 1 cup = 240 ml. i

Radda [10]

The mass is simply the product of volume and density. But first, let us convert the volume into cm^3 (cm^3 = mL):

volume = 2.5 cups * (240 mL/cup)

volume = 600 mL = 600cm^3

So the mass is:

mass = 600 cm^3 * (1 g / cm^3)

6 0

4 years ago

A 1.10 g sample contains only glucose and sucrose. When the sample is dissolved in water to a total solution volume of 25.0L, th

olga_2 [115]

Answer:

$\large \boxed{79 \, \%}$

Explanation:

I assume the volume is 2.50 L. A volume of 25.0 L gives an impossible answer.

We have two conditions:

(1) Mass of glucose + mass of sucrose = 1.10 g

(2) Osmotic pressure of glucose + osmotic pressure of sucrose = 3.78 atm

Let g = mass of glucose

and s = mass of sucrose. Then

g/180.16 = moles of glucose, and

s/342.30 = moles of sucrose. Also,

g/(180.16×2.50) = g/450.4 = molar concentration of glucose. and

s/(342.30×2.50) = s/855.8 = molar concentration of sucrose.

1. Set up the osmotic pressure condition

Π = cRT, so

$\begin{array}{rcl}\Pi_{\text{g}} +\Pi_{\text{s}}&=&\Pi_{\text{tot}}\\\dfrac{g}{450.4}\times8.314\times298 + \dfrac{s}{855.8}\times8.314\times298 & = & 3.78\\\\5.501g + 2.895s & = & 3.78\\\end{array}$

Now we can write the two simultaneous equations and solve for the masses.

2. Calculate the masses

$\begin{array}{lrcl}(1)& g + m & = & 1.10\\(2) &5.501g +2.895s & = & 3.78\\(3) & m & = &1.10 - g\\&5.501g + 2.895(1.10 - g) & = & 3.78\\&2.606g + 3.185 & = & 3.78\\ &2.606g & = & 0.595\\(4) & g & = & \mathbf{0.229}\\&0.229 + s & = & 1.10\\& s & = & \mathbf{0.871}\\\end{array}$

We have 0.229 g of glucose and 0.871 g of sucrose.

3. Calculate the mass percent of sucrose

$\text{Mass percent} = \dfrac{\text{Mass of component}}{\text{Total mass}} \times \, 100\%\\\\\text{Percent sucrose} = \dfrac{\text{0.871 g}}{\text{1.10 g}} \times \, 100\% = 79 \, \%\\\\\text{The mixture is $\large \boxed{\mathbf{79 \, \%}}$ sucrose}$

6 0

3 years ago

Which statement describes a chemical property of

wel

everything describes physical traits ect. and 3 explains reactions with a different substance so 3

4 0

3 years ago