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3 years ago

Select the correct answer

Chemistry

1 answer:

Semmy [17]3 years ago

3 0

Answer:

Explanation:

Silicon, element number 14 is the fourth element in the third period in the periodic table. Its electronic configuration is 1s^2 2s^2 2p^6 3s^2 3p^2.

The elemental symbol of the previous noble gas preceding the atom is replaced by the arrangement of the remaining electrons to form a noble gas configuration of an atom.

So for Silicon, we substitute [Ne] 1s^2 2s^2 2p^6 and the noble gas configuration can now be [Ne] 3s^2 3p^2.

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If 1.27 moles of bromine gas (Br2) react with excess phosphorus (P), how many moles of phosphorus tribromide (PBr3) will be prod

frez [133]

Answer:

0.85 mole of PBr3.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

3Br2 + 2P —> 2PBr3

From the balanced equation above,

3 moles of Br2 reacted to produce 2 moles of PBr3.

Therefore, 1.27 moles of Br2 will react to produce = (1.27 x 2)/ 3 = 0.85 mole of PBr3.

Therefore, 0.85 mole of PBr3 is produced by the reaction.

8 0

3 years ago

Indicate which molecules demonstrate the correct bonding for carbon atoms. Check all that apply.

nirvana33 [79]

Answer:

CH4 and CH3 CH2 CH2 CH3

Explanation:

4 0

3 years ago

Read 2 more answers

Calculate the molality of the salt solution. Express your answer to four significant figures and include the appropriate units.

Thepotemich [5.8K]

Answer:

m = 2.955x10⁻² mol/kg

X = 5.323x10⁻⁴ mol NaCl/Total moles

(w/w)% = 0.1726%

ppm = 1726 mg/kg

Explanation:

Molality is the ratio between moles of solute per kg of solution.

As the solution is 2.950×10⁻² mol/L, mililters are 999.2mL and density is 0.9982 g/mL, molality is:

m = 2.950×10⁻² mol/L×(1L/0.9982kg) = 2.955x10⁻² mol/kg

Mole fraction is moles of NaCl/total moles.

Moles of H₂O are:

999.2mL×(0.9982g/mL)×(1mol/18,02g) = 55,35 moles of H₂O

Moles of NaCl are:

2.950×10⁻² mol/L×(0.9992L)= 2.950×10⁻² mol of NaCl

mole fraction is:

X = 2.950×10⁻² mol of NaCl / (2.950×10⁻² mol of NaCl+55.35mol water) = 5.323x10⁻⁴ mol NaCl/Total moles

Mass of NaCl is:

2.950×10⁻² mol of NaCl×(58.44g/mol) = 1.724g of NaCl

Mass of water is:

55.35mol water×(18.02g/mol) = 997.4g of H₂O

(w/w)% is:

1.724g of NaCl / (1.724g of NaCl+997.4g of H₂O) ×100 = 0,1726%

Parts per million is mg of NaCl per kg of solution, that is:

1724mg of NaCl / 0.999124g = 1726 ppm

I hope it helps!

5 0

3 years ago

The empirical formula for trichloroisocyanuric acid, the active ingredient in many household bleaches is OCNCI. The molar mass o

TEA [102]

Answer:

These two are equivalent and valid:

$C_3Cl_3N_3O_3$

$Cl_3(CN)_3O_3$

Explanation:

The molecular superscripts for each atom in the molecular formula are determined by the number of times that the mass of the empirical formula is contained in the molar mass.

1. Determine the mass of the empirical formula:

$OCNCl$ :

Atomic masses:

O: 15.999g/mol
C: 12.011g/mol
N: 14.007g/mol
Cl: 35.453g/mol

Total mass:

15.999g/mol + 12.011g/mol + 14.007g/mol + 35.453g/mol = 77.470g/mol

2. Divide the molar mass by the mass of the empirical formula:

232.41g/mol / 77.470g/mol = 3

3. Multiply each superscript of the empirical formula by the previous quotient: 3

$O_3C_3N__3Cl_3$

Or:

$C_3Cl_3N_3O_3$

You might also write CN as a group:

$Cl_3(CN)_3O_3$

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3 years ago

Which of the following are forms of asexual reproduction? select three options

lara31 [8.8K]

Brain fission. Budding. Fragmentation

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4 years ago