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3 years ago

What is the name of the compound Si5F7?

Chemistry

2 answers:

Drupady [299]3 years ago

6 0

Answer:

silicone flourine? it can aslo be Pentasilicon hexafluoride

Explanation:

vlabodo [156]3 years ago

5 0

Answer:

To distinguish these compounds from each other, Greek prefixes are used to designate the numbers of atoms of one or both elements in the molecule. Therefore, CO2 is called carbon dioxide and CO is called carbon monoxide; SO2 is sulfur dioxide and SO3 is sulfur trioxide.

Explanation:

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An (blank) determines what will be tested in a scientific experiment

elixir [45]

The answer would be hypotheis since its an theory that isnt proven yet which would involve a scientist to expertiment to make the hypothesis true or valid

6 0

3 years ago

A chemist must prepare of potassium hydroxide solution with a pH of at . He will do this in three steps: Fill a volumetric flask

maksim [4K]

The question is incomplete; the complete question is:

A chemist must prepare 800.0mL of potassium hydroxide solution with a pH of 13.00 at 25 degree C. He will do this in three steps: Fill a 800.0mL volumetric flask about halfway with distilled water. Weigh out a small amount of solid potassium hydroxide and add it to the flask. Fill the flask to the mark with distilled water. Calculate the mass of potassium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits.

Answer:

4.5g (to 2 significant digits)

Explanation:

Now we must remember that KOH is a strong base, therefore it will practically dissociate completely.

To find the pH we can use the equation pH + pOH = 14.

Firstly to find the pOH:

13.00 + pOH = 14

pOH = 1.00

To find the [OH-]

Since

pOH= -log[OH^-]

[OH^-] = antilog (-pOH)

[OH^-]= antilog (-1)

[OH^-] = 0.1 molL-1

Since we've established that KOH is a strong base, we know that [OH-] = [KOH]

Also, we know that concentration = number of moles/volume

we have the concentration and the volume now so we can calculate the number of number of moles as follows:

The 800mL volume is the same as 0.8L

0.1 molL-1= number of moles/0.8L

0.08 moles = number of moles

now we can calculate the amount of solid KOH required

the molar mass of KOH = 39 + 16 +1 = 56 gmol-1

56 x 0.08 moles = 4.48g

So in 800mL of pH 13.00 KOH there is 4.5g of KOH dissolved.

3 0

3 years ago

At 25 ∘C , the equilibrium partial pressures for the reaction were found to be PA=5.16 bar, PB=5.04 bar, PC=4.11 bar, and PD=4.8

erastova [34]

Answer: 5.85kJ/Kmol.

Explanation:

The balanced equilibrium reaction is

$A(g)+2B(g)\rightleftharpoons 4C(g)+D(g)$

The expression for equilibrium reaction will be,

$K_p=\frac{[p_{D}]\times [p_{C}]}^4{[p_{B}]^2\times [p_{A}]}$

Now put all the given values in this expression, we get the concentration of methane.

$K_p=\frac{(4.85)\times [(4.11)^4}{(5.04)^2\times (5.16)}$

$K_p=10.6$

Relation of standard change in Gibbs free energy and equilibrium constant is given by:

$\Delta G^o=-2.303\times RT\times \log K_c$

where,

R = universal gas constant = 8.314 J/K/mole

T = temperature = $25^0C=(25+273)K=298 K$

$K_c$ = equilibrium constant = 10.6

$\Delta G^o=-2.303\times 8.314\times 298\times \log (10.6)$

$\Delta G^o=5850.23J/Kmol$

$\Delta G^o=5.85kJ/Kmol$

Thus standard change in Gibbs free energy of this reaction is 5.85kJ/Kmol.

3 0

3 years ago

Sulfur dioxide, SO 2 ( g ) , can react with oxygen to produce sulfur trioxide, SO 3 ( g ) , by the reaction 2 SO 2 ( g ) + O 2 (

aleksley [76]

<u>Answer:</u> The amount of heat produced by the reaction is -21.36 kJ

<u>Explanation:</u>

Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles.

The equation used to calculate enthalpy change is of a reaction is:

$\Delta H^o_{rxn}=\sum [n\times \Delta H_f_{(product)}]-\sum [n\times \Delta H_f_{(reactant)}]$