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frozen [14]
3 years ago
6

The classification of elements in the periodic table is mainly based on ​

Chemistry
1 answer:
Allushta [10]3 years ago
8 0

Answer:

atomic number

Each period, numbered one through seven, contains elements of increasing atomic number. Unlike Mendeleev's original list, the modern periodic table is based on atomic number, or the number of protons in an element's atomic nucleus

Explanation:

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The decomposition of dinitrogen pentoxide, N2O5, to NO2 and O2 is a first-order reaction. At 60°C, the rate constant is 2.8 × 10
Ugo [173]

Answer:

The correct option is a.

Explanation:

2N_2O_5\rightarrow 4NO_2 + O_2

125 kPa

125kpa - 2x                            4x    x

Total pressure after reaction = 176 kPa

125 kPa - 2x + 4x + x = 176 kPa

x = 17

125 kpa - 2x = 125 kPa - 2(17) = 91 kPa

Initial pressure of the dinitrogen pentoxide ,(at t=0) =P_o= 125 kPa

Final pressure of the dinitrogen pentoxide, (at t = t) = P = 91 kPa

The rate constant is = k = 2.8\times 10^{-3} min^{-1}

t=\frac{2.303}{k}\log\frac{P_o}{P}

t=\frac{2.303}{2.8\times 10^{-3} min^{-1}}\log\frac{125 kPa}{91 kPa}

t=113.3969 minutes\approx 113 minutes

It will take 113 minutes for the total pressure to reach 176 kPa.

8 0
3 years ago
What two gases make up 99% of the Earth's atmosphere? A. Nitrogen and water vapor B. Carbon dioxide and oxygen C. Carbon dioxide
denpristay [2]

Of the gases listed, nitrogen, oxygen, water vapor, carbon dioxide, methane, nitrous oxide, and ozone are extremely important to the health of the Earth's biosphere. The table indicates that nitrogen and oxygen are the main components of the atmosphere by volume.

so the answer is D. Nitrogen and oxygen

hope this helps!

6 0
3 years ago
The solubility of copper(i) chloride is 3.91 mg per 100.0 ml of solution. calculate ksp for cucl (cucl=99.00 g mol-1).
garri49 [273]
Convert  Mg  to  grams
1g =1000mg  what  about  3.91  Mg
=  3.91mg  x  1g/1000mg=  3.91  x10^-3 g
moles= mass/molar mass
that  is  3.91  x10^-3g  /99 g/mol=3.95 x10^-5moles
concentration=   moles  /  vol   in  liters

that  is  3.95  x10^-5/100  x1000=  3.94  x10^-4M

equation for  dissociation  of  CUCl=   CUCl---->  CU^+   +Cl^-

Ksp=(CU+)(CI-)
that  is  (3.95  x10^-4)(3.95  x10^-4)
Ksp=  1.56  x10^-7
3 0
3 years ago
Read 2 more answers
A dilute solution of bromine in carbon tetrachloride behaves as an ideal-dilute solution. The vapour pressure of pure CCl4 is 33
ANEK [815]

Explanation:

The given data is as follows.

     Vapour pressure of pure CCl_{4} = 33.85 Torr

         Temperature = 298 K

      Mole fraction of Br_{2} = 122.36 torr

Therefore, calculate the vapor pressure of Br_{2} as follows.      

     Vapour pressure of Br_{2} = mole fraction of Br_{2} x K of Br_{2}

                                    = 0.050 x 122.36 Torr

                                   = 6.118 Torr

So, vapor pressure of Br_{2} is 6.118 Torr .

Now, calculate the vapor pressure of carbon tetrachloride as follows.

     Vapour pressure of CCl_{4} = mole fraction of CCl_{4} x Pressure of CCl_{4}

                                     = (1 - 0.050) × 33.85 Torr

                                     = 32.1575 Torr

So, vapor pressure of CCl_{4} is 32.1575 Torr  .

Hence, the total pressure will be as follows.

                         = 6.118 Torr + 32.1575 Torr

                         = 38.2755 Torr

Therefore, composition of CCl_{4} = \frac{32.1575 Torr}{38.2755 Torr}

                         = 0.8405

Composition of CCl_{4} is 0.8405 .

And, composition of Br_{2} = \frac{6.118 Torr}{38.2755 Torr}

                                                  = 0.1598

Composition of Br_{2} is 0.1598 .

6 0
3 years ago
Sterling silver is 92.5% silver and 7.5% copper. Its density is 10.25 g/cm3. A sterling silver pendant is added to a graduated c
Mariulka [41]

From the information given:

  • The volume of the graduated cylinder = 50.0 mL
  • when a sterling silver pendant is added, the volume increases to = 61.3 mL

∴

The volume of the sterling silver pendant is:

= 61.3 mL - 50.0 mL

= 11.3 mL

Since, 1 mL = 1cm³

Then;

11.3 mL = 11.3 cm³

  • the density of the sterling silver = 10.25 g/cm³

Using the relation for Density; i.e.

\mathbf{Density = \dfrac{mass}{volume}}

\mathbf{10.25 \ g/cm^3= \dfrac{mass}{11.3  \ cm^3}}

mass = 10.25 g/cm³× 11.3 cm³

mass of the sterling silver = 115.825 grams

Recall that sterling silver has:

  • 92.5% silver and;
  • 7.5% copper

∴

The mass of the copper contained in the sterling silver pendant can be calculated as:

\mathbf{= \dfrac{115.825  \ g \times 7.5}{100}}

= 8.687 grams

Therefore, we can conclude that the mass of the copper contained in the sterling silver pendant is 8.687 grams

Learn more about the relation between Density, Mass, and Volume here:

brainly.com/question/24386693?referrer=searchResults

4 0
2 years ago
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