Is a soap solution with a pH of 9 acidic, base, or neutral?

A student mixed a small amount of iron filings and sulphur powder in a dish. He could not

Temka [501]

Answer:

$\huge \boxed{\mathrm{Carbon \ disulphide}}$

Explanation:

Carbon disulphide is the liquid that can be used to separate iron fillings and sulphur powder.

When carbon disulphide is poured into the dish, the sulphur powder gets easily dissolved in the carbon disulfide. The iron fillings are left to settle on the bottom of the dish.

The iron fillings can get seperated through filtration. When the mixture of sulphur powder and carbon disulphide gets completely evaporated, the sulphur powder is left over.

7 0

3 years ago

If a pork roast must absorb kJ to fully cook, and if only 10% of the heat produced by the barbecue is actually absorbed by the r

kolezko [41]

Answer:

1,033.56 grams of carbon dioxide was emitted into the atmosphere.

Explanation:

$C_3H_8(g)+5O_2(g)\rightarrow 3CO_2(g)+4H_2O(g),\Delta H_{rxn}=-2044 kJ/mol (assuming)$

Energy absorbed by pork,E = $1.6\times 10^3 kJ$ (assuming)

Total energy produced by barbecue = Q

Percentage of energy absorbed by pork = 10%

$10\%=\frac{E}{Q}\times 100$

$Q=\frac{E}{10}\times 100=\frac{1.6\times 10^3 kJ}{10}\times 100=1.6\times 10^4 kJ$

Since, it is a energy produced in order to indicate the direction of heat produced we will use negative sign.

Q = $-1.6\times 10^4 kJ$

Moles of propane burnt to produce Q energy =n

$n\times \Delta H_{rxn}=Q$

$n=\frac{Q}{\Delta H_{rxn}}=\frac{-1.6\times 10^4 kJ}{-2044 kJ/mol}=7.83 mol$

According to reaction , 1 mol of propane gives 3 moles of carbon dioxide. then 7.83 moles of will give:

$\frac{1}{3}\times 7.83 mol=23.49 mol$ carbon dioxide gas.

Mass of 23.49 moles of carbon dioxide gas:

23.49 mol × 44 g/mol =1,033.56 g

1,033.56 grams of carbon dioxide was emitted into the atmosphere.

8 0

3 years ago

Which particles determine the atomic number of the nucleus? which determine the atomic weight?

Alexxx [7]

Hi there ,
Electron represents atomic number.
Protron and Neutron determine the weight.
Hope it helps.

3 0

3 years ago

How many moles of NaCl are there in 6.93g?

kkurt [141]

8.43
58.44g/mol*1/6.93g= 8.43moles of NaCL

5 0

3 years ago

Anything in red is the question

solmaris [256]

Answer:

19. C₂H₂, HF, and H₂O₂ are molecular compounds

20. The formula is CuSO₄. 5H₂O

Explanation:

Question 19.

The three the chemical formulae in red, C₂H₂, HF, and H₂O₂, represent compounds because a compound is the chemical union of two or more atoms of different kind.

The chemical union is done either by ionic bonds or covalent bonds.

C, H, F, and O are all non-metal elements. Non-metals combine each other through covalent bonds, which is the bond in which electrons are shared to complete the valence shell. Ionic bonds are formed by the electrostatic atraction between ions of different charge and is typical of the bond between a metal and a non-metal.

Thus, all the bonds are covalent and the compounds are molecular compounds.

Question 20.

You can determine the chemical formula using the molar masses of both Copper(II) sulfate and water.

Molar mass of copper(II) sulfate: 159.609 g/mol
Molar mass of water: 18.015 g/mol

Call n the number of water molecules in the molecular formula:

CuSO₄ . nH₂O

The ratio of water to copper(II) sulfate is:

n × molar mass of water / molar mass of the compound

n × 18.015 / (n × 18.015 + 159.609) = 36%

18.015n = 0.36(18.015n + 159.609)

18.015n = 6.4854n + 57.45924

11.5296n = 57.45924

n = 4.9836 ≈ 5

Therefore, the formula of the hydrate contains 5 molecules of water and it is CuSO₄.5H₂O.

8 0

3 years ago