All categories

3 years ago

I need help with this:

Chemistry

2 answers:

earnstyle [38]3 years ago

4 0

1 send astronauts to space and saw the earth round

2 saying something to do

3 science that been solved

4 science had have no evidence

5 have proved and stories

Airida [17]3 years ago

4 0

I am pretty sure that all your answers are correct.

You might be interested in

Difference between emprical and molecular formula

Musya8 [376]

Answer:

The key difference between empirical and molecular formulas is that an empirical formula only gives the simplest ratio of atom whereas a molecular formula gives the exact number of each atom in a molecule.

3 0

2 years ago

A rigid vessel contains 3.98 kg of refrigerant-134a at 700 kPa and 60°C. Determine the volume of the vessel and the total intern

Arada [10]

Answer: The volume of the vessel is $0.1542m^3$ and total internal energy is 162.0 kJ.

Explanation:

To calculate the volume of water, we use the equation given by ideal gas, which is:

$PV=nRT$

or,

$PV=\frac{m}{M}RT$

where,

P = pressure of container = 700 kPa

V = volume of container = ? L

m = Given mass of R-134a = 3.98 kg = 3980 g (Conversion factor: 1kg = 1000 g)

M = Molar mass of R-134a = 102.03 g/mol

R = Gas constant = $8.31\text{L kPa }mol^{-1}K^{-1}$

T = temperature of container = $60^oC=[60+273]K=333K$

Putting values in above equation, we get:

$700kPa\times V=\frac{3980g}{102.03g/mol}\times 8.31\text{L kPa }\times 333K\\\\V=154.21L$

Converting this value into $m^3$ , we use the conversion factor:

$1m^3=1000L$

So, $\Rightarrow (\frac{1m^3}{1000L})\times 154.21L$

$\Rightarrow 0.1542m^3$

To calculate the internal energy, we use the equation:

$U=\frac{3}{2}nRT$

or,

$U=\frac{3}{2}\frac{m}{M}RT$

where,

U = total internal energy

m = given mass of R-134a = 3.98 kg = 3980 g (Conversion factor: 1kg = 1000g)

M = molar mass of R-134a = 102.03 g/mol

R = Gas constant = $8.314J/K.mol$

T = temperature = $60^oC=[60+273]K=333K$

Putting values in above equation, we get:

$U=\frac{3}{2}\times \frac{3980g}{102.03g/mol}\times 8.314J/K.mol\times 333K\\\\U=161994.6J$

Converting this into kilo joules, we use the conversion factor:

1 kJ = 1000 J

So, 161994.6 J = 162.0 kJ

Hence, the volume of the vessel is $0.1542m^3$ and total internal energy is 162.0 kJ.

6 0

3 years ago

Elements in a given period of the periodic table contain the same number of

leva [86]

Its C, Outermost Electrons.

4 0

3 years ago

EXPERIMENT: DETERMINING VOLUME

Tanzania [10]

Explanation:

(Ques- A) Why does the first method for determining volume work only for a regular-shaped object?

(Ans- A) Because the method requires precise dimensions of objects for result, which is not possible for irregular shaped objects.

(Ques - B) Will the second method for determining volume work for any object or just an odd-shaped one? Why?

(Ans-B) It will work for both regular and irregular shaped objects since both displace equal volumes of water.

(Ques - C) Is one method of measurement more accurate than the other? Why or why not?

(Ans-C) Both are pretty accurate, with some experimental errors which may creep in accidentally.

(Ques- D) Would the displacement method of measurement work for a cube of sugar? What about a cork? Why?

(Ans - D) No, the method would not work because sugar being soluble, will dissolve in water.

No, the method would not work because sugar being soluble, will dissolve in water. Cork is less dense than water so floats on it, with only part of it submerged in water, resulting in displacement of less volume of water than actual volume of Cork.

(Ques-E) What did you find out from this investigation? Be thoughtful in your answer.

(Ans- E) I learnt about determining volume of different objects from this investigation. (Sorry, I know its not a very thoughtful answer)

7 0

3 years ago

Based on the name, which substance is a covalent compound?

jek_recluse [69]

Compounds that has two elements on the formula can be bonded by ionic or covalent bond. If the compound is a metal and a non-metal then it will be ionic bonding. However, when it involves two non-metals, then it will have covalent bonding.

3 0

3 years ago