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4 years ago

Determining Density and Using Density to Determine Volume or Mass

Chemistry

1 answer:

Shalnov [3]4 years ago

4 0

corrected question:

Determining Density and Using Density to Determine Volume or Mass

(a) Calculate the density of mercury if 1.00 × 10 g occupies a volume of 7.36 cm³

(b) Calculate the volume of 65.0 g of liquid methanol (wood alcohol) if its density is 0.791 g/mL.

(d) Calculate the density of a 374.5-g sample of copper if it has a volume of 41.8 cm³ A student needs 15.0 g of ethanol for an experiment. If the density of ethanol is 0.789 g/mL, how many milliliters of ethanol are needed? What is the mass, in grams, of 25.0 mL of mercury (density = 13.6 g/mL)?

Answer:

density = $\frac{mass}{volume}$

ρ=m/v ,m=ρv, v=m/ρ

(a)m=1*10g , v=7.36cm³

ρ=10/7.36 =1.36g/cm³

(b) m=65g, ρ=0.791 g/mL.

v= 65/0.791 =82.17g/mL

m=19..32*8=154.56g/cm³

(d) mass of copper=374.5g , v=41.8cm³

ρ=374.5/41.8 =8.96g/cm³

mass of ethanol=15g, density of ethanol=0.789g/mL

v=15/0.789 =19.01mL

volume of mecury=25mL, density of mercury=13.6g/mL

m=25*13.6=340g

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4 years ago

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2 years ago

Which action would shift this reaction away from solid calcium fluoride and toward the dissolved ions?a) adding calcium ionsb) a

Mila [183]

Answer:

c) removing fluoride ions.

Explanation:

Hello!

In this case, for this solubility product problem, it is very convenient to write the undergoing ionization reaction:

$CaF_2(s)\rightleftharpoons Ca^{2+}(aq)+2F^-(aq)$

In such a way, via the Le Chatelier's principle, we remember that the addition of reactants shifts the reaction towards products, adding products shifts the reaction towards reactants, removing reactants shifts the reaction towards reactants and removing products shifts the reaction towards products. In means, that the best way to shift this reaction away from solid calcium fluoride and toward the dissolved ions is c) removing fluoride ions, because it is a product and its removal favors the formation of more products.

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3 years ago

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Answer:

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4 years ago

How much energy (in J) is lost when a sample of iron with a mass of 26.4 g cools from 74.0 ∘C to 26.0 ∘C?

Greeley [361]

Answer:

$Q=-526.6J$

Explanation:

Hello,

In this case, for the computation of the energy loss when the cooling process is carried out, we use the shown below equation:

$Q=mCp\Delta T$

Whereas we need the mass, specific heat and change in temperature of iron within the process. Thus, the only value we need is the specific heat that is 0.444 J/(g°C), therefore, we compute the heat loss:

$Q=26.4g*0.444\frac{J}{g\°C}*(26.0\°C-74.0\°C)\\ \\Q=-526.6J$

Negative sign points out the loss due to the cooling.

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