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2 years ago

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Which of these outcomes is conclusive evidence that mixing sugar in water is a physical change? There is no change in color. The

re is no precipitate formed. There is no gas given off. There is no molecular change.

1 answer:

Gelneren [198K]2 years ago

8 0

Well, the sugar is dissolving in the water as you mix it which is a physical change.

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An unknown compound is processed using elemental analysis and found to contain 117.4g of platinum 28.91 carbon and 33.71g nitrog

dlinn [17]

Answer:

1 mole of platinum

Explanation:

To obtain the number of mole(s) of platinum present, we need to determine the empirical formula for the compound.

The empirical formula for the compound can be obtained as follow:

Platinum (Pt) = 117.4 g

Carbon (C) = 28.91 g

Nitrogen (N) = 33.71 g

Divide by their molar mass

Pt = 117.4 / 195 = 0.602

C = 28.91 / 12 = 2.409

N = 33.71 / 14 = 2.408

Divide by the smallest

Pt = 0.602 / 0.602 = 1

C = 2.409 / 0.602 = 4

N = 2.408 / 0.602 = 4

The empirical formula for the compound is PtC₄N₄ => Pt(CN)₄

From the formula of the compound (i.e Pt(CN)₄), we can see clearly that the compound contains 1 mole of platinum.

8 0

2 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

2 years ago

Describe the difference between gravitational force and strong nuclear force

arsen [322]

Gravitational force is much weaker, because it is the force of gravity, or the force that makes smaller objects be pulled towards a much bigger one with a certain amount of force.

Now strong nuclear force, which is very strong, keeps the atomic particles in an atom from separating, and the reason it is so powerful is because the particles in an atom repel each other and this force keeps them from doing .that

6 0

2 years ago

Why are cells the building blocks of an organism.

ladessa [460]

Answer:A cell is the smallest unit of life, also called the 'building blocks of life' because cells multiply and differentiate to form a multicellular organism as well as give rise to new organism by forming gametes or reproductive spores.

Explanation:

8 0

2 years ago

`You have to be careful about pouring drano down your pipes since it is mainly hydrochloric acid--you can't do it if they are ma

Zanzabum

Answer:

6.67 moles

Explanation:

Given that:-

Moles of hydrogen gas produced = 10.0 moles

According the reaction shown below:-

$2Al + 6HCl\rightarrow 2AlCl_3 +3H_2$

3 moles of hydrogen gas are produced when 2 moles of aluminium undergoes reaction.

Also,

1 mole of hydrogen gas are produced when $\frac{2}{3}$ moles of aluminium undergoes reaction.

So,

10.0 moles of hydrogen gas are produced when $\frac{2}{3}\times 10.0$ moles of aluminium undergoes reaction.

<u>Moles of Al needed = $\frac{2}{3}\times 10.0$ moles = 6.67 moles</u>

6 0

2 years ago