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deff fn [24]
4 years ago
7

A compound contains 40% calcium, 12% carbon, and 48% oxygen by mass. What is the empirical formula of this compound?

Chemistry
1 answer:
jasenka [17]4 years ago
3 0

Answer:

<em>CaCO3</em>

Explanation:

E.F. is looking for the lowest possible ratio

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What is the molar mass of CoH1206
Irina18 [472]
Molar mass of COH1206 is 1243.5857 g/mol
3 0
3 years ago
Read 2 more answers
What is the standard gibbs free energy for the transformation of diamond to graphite at 298 k? cdiamondâcgraphite?
denis-greek [22]
Considering; graphite; standard enthalpy = 0 and entropy = 5.740; diamond standard enthalpy = 1.897 and entropy = 2.38.
Using the equation Delta G = Delta H - Temperature (DeltaS)
Delta H = enthalpy sum of products - enthalpy sum of reactants
Which will be; 0 -1.897 = -1.897 kJ/Mol
Delta S is the entropy sum; given by 
5.740 - 2.38 = 3.36 J/Mol
We can convert Delta S from Joules to kilo Joules by dividing by 1000
we get ; 0.00336 kJ/mol
We are given a temperature in kelvin which suits the calculations ((298 k)
Therefore; using the equation; 
= -1.897 - (298 × 0.00336) = -2.90 kJ
Thus; the standard gibbs free energy will be; -2.9 kJ

5 0
3 years ago
Chemist preformed Reaction of solid magnesium burning and found that the mass of the magnesium oxide what is greater than the ma
tankabanditka [31]

Answer:

The magnesium reacted with the oxygen in the air.

Explanation:

For argument’s sake, let’s say that the mass of magnesium oxide was 3 g and that of the oxide was 5 g.  

The reaction was

            magnesium + oxygen ⟶ magnesium oxide

Mass:           3 g                                          5 g

Mass of oxygen = 5 g – 3 g = 2 g

The 3 g of magnesium must have combined with 2 g of oxygen to form 5 g of magnesium oxide.

4 0
3 years ago
The acid-dissociation constant of hydrocyanic acid (hcn) at 25.0 °c is 4.9 ⋅ 10−10. what is the ph of an aqueous solution of 0.0
vodomira [7]
According to the reaction equation:

and by using ICE table:

              CN-  + H2O ↔ HCN  + OH- 

initial  0.08                        0          0

change -X                        +X          +X

Equ    (0.08-X)                    X            X

so from the equilibrium equation, we can get Ka expression

when Ka = [HCN] [OH-]/[CN-]

when Ka = Kw/Kb

               = (1 x 10^-14) / (4.9 x 10^-10)

               = 2 x 10^-5

So, by substitution:

2 x 10^-5 = X^2 / (0.08 - X)

X= 0.0013

∴ [OH] = X = 0.0013 

∴ POH = -㏒[OH]

            = -㏒0.0013

            = 2.886 

∴ PH = 14 - POH

         = 14 - 2.886 = 11.11
5 0
3 years ago
At which temperature do the molecules of an ideal gas have 3 times the kinetic energy they have at 32of?
algol [13]

Answer:

  • 820 K

Explanation:

As per Boltzman equation, <em>kinetic energy (KE)</em> is in direct relation to the <em>temperature</em>, measured in absolute scale Kelvin.

  • KE α T.

Then, <em>the temperature at which the molecules of an ideal gas have 3 times the kinetic energy they have at any given temperature will be </em><em>3 times</em><em> such temperature.</em>

So, you must just convert the given temperature, 32°F, to kelvin scale.

You can do that in two stages.

  • First, convert 32°F to °C. Since, 32°F is the freezing temperature of water, you may remember that is 0°C. You can also use the conversion formula: T (°C) = [T (°F) - 32] / 1.80

  • Second, convert 0°C to kelvin:

         T (K) = T(°C) + 273.15 K= 273.15 K

Then, <u>3 times</u> gives you: 3 × 273.15 K = 819.45 K

Since, 32°F has two significant figures, you must report your answer with the same number of significan figures. That is 820 K.

7 0
3 years ago
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