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2 years ago

Select two that are true

Chemistry

1 answer:

Inessa [10]2 years ago

8 0

Answer:

The two that are true are, "this represents a pure compound in two different states" and "it represents a mixture a solid and a gas".

Explanation:

This two are concluded only from the picture and the use of uniform colors throughout the picture (Showing the same element).

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A 0.750-g sample of a compound that might be iron(II) chloride, nickel(II) chloride, or zinc chloride is dissolved in water, and

DedPeter [7]

Answer: The compound is nickel (II) chloride.

NiCl2

Explanation:

Let's assume that the compound is X.

Then,

XCl2 + 2AgNO3 ---> X(NO3)2 + 2AgCl

Given,

Volume of AgNO3 = 22.4ml = 0.0224L

Concentration of AgNO3 = 0.515M

no of moles = concentration x volume

:• n(AgNO3) = 0.515 x 0.0224

n(AgNO3) = 0.011536 mol

Therefore, no of moles of AgNO3 is 0.0011536mol

From the equation above, we can deduce that;

n(XCl2) = 1/2n(AgNO3)

:• n(XCl2) = 1/2 × 0.011536

n(XCl2) = 0.005768

Therefore number of moles of XCl2 is 0.005768 mol.

Mass, m, of XCl2 = 0.75g (Given)

Molar mass = mass/ no of moles

Molar mass of XCl2 = 0.75/0.005768

:• molar mass of XCl2= 130.03g/mol

Molar mass of Cl = 35.453

Cl2= 2 x 35.453 = 70.906

Molar mass of XCl2 = M.mass of X +

M.mass of Cl2

:• 130.03 = M.mass of X + 70.906

Molar mass of X = 130.03 - 70.906

Molar mass of X = 59.1

By comparing to literature, we can conclude that X is Nickle ,Ni.

Therefore, the compound is NiCl2 , Nickle(II) Chloride.

4 0

3 years ago

Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the equation: CO2(s)→CO2(g). Whe

MA_775_DIABLO [31]

Answer:

6.82 kg

Explanation:

Given that the amount of water is 15L and we know that the density of water is ≈ 1kg/L. The mass of water is given by mass = volume x density, i.e,

mass = 15 x 1 = 15 kg. Also the specific heat capacity of water is 4.186 KJ/kg.

The sublimation enthalpy of dry ice is 571 KJ/kg.

Now, the amount of heat lost by water is entirely used up for the sublimation (conversion from soild to gas) of dry ice. And the heat (Q) lost by water is given as : Q = mCΔT, where m is the mass of water, C the specific heat capacity of water and ΔT the change in temperature.

Here, Q = 15 x 4.186 x (90 - 28) = 3892.98 KJ.

This amount of heat is taken up by the dry ice for its sublimation. Also the energy taken by dry ice (Q') for its sublimation is given by: Q' = m'L', where m' is the mass of dry ice, L' is the latent heat of sublimation (i.e, the amount of heat required per kg of a substance to sublime) of dry ice amd L' = 571 KJ/kg.

Now, Q' =m'L' = heat lost by water = 3892.98KJ.

And, m'L' = m' x 571 KJ/kg = 3892.98 KJ. (Dividing with 571)

Therefore, m' = 6.82 kg.

6 0

3 years ago

Suppose a platinum atom in the oxidation state formed a complex with two chloride anions and two ammonia molecules. Write the ch

Korolek [52]

Answer: Pt(Cl)2(NH3)2

Explanation:

In the formation of the complex, the oxidation number of platinum is plus two (+2) and two chloride ions cancel it out by their oxidation number of -1 each. Hence the complex has an overall charge of zero. It is thus neutral with no charge attached to its formula.

7 0

3 years ago

what might cause the goldfish population to drop if the temperature moves out of its normal range? Name three things

Slav-nsk [51]

Answer:

Appearing disoriented, such as swimming upside down.

Leaving food uneaten.

White spots on fins or body.

Discolored gills.

Explanation:

Gold Fish are unable to regulate their body temperature, so they are influenced by the temperature around them. If the water is warm, gold fish metabolism accelerates, feeding and respiration increases, and there is a general increase in movement. If the water is cooler, fish become lethargic and tend to be inactive.

8 0

3 years ago

A 50 W engine generates 50 J of energy. How long did it run for?

Inessa [10]

The engine ran for 10 second

6 0

3 years ago

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