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3 years ago

Which of the following is an indication of a physical change?

Chemistry

2 answers:

blagie [28]3 years ago

6 0

I would like to say c

Elan Coil [88]3 years ago

5 0

Answer:

A change in the shape of a substance

Explanation:

Because when ths shape of a sunstance changes , its physical appearance changes .A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.

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Heating 2.40 g of the oxide of metal X (molar mass of X = 55.9 g/mol) in carbon monoxide (CO) yields the pure metal and carbon d

Korolek [52]

Answer:The molecular formula of the oxide of metal be $X_2O_3$ . The balanced equation for the reaction is given by:

$X_2O_3+3CO\rightarrow 3CO_2+2X$

Explanation:

Let the molecular formula of the oxide of metal be $X_2O_y$

$X_2O_y+yCO\rightarrrow yCO_2+2X$

Mass of metal product = 1.68 g

Moles of metal X = $\frac{1.68 g}{55.9 g/mol}=0.03005 mol$

1 mol of metal oxide produces 2 moles of metal X.

Then 0.03005 moles of metal X will be produced by:

$\frac{1}{2}\times 0.03005 mol=0.01502 mol$ of metal oxide

Mass of 0.01502 mol of metal oxide = 2.40 g (given)

$0.01502 mol\times (2\times 55.9 g/mol+y\times 16 g/mol)=2.40 g$

y = 2.999 ≈ 3

The molecular formula of the oxide of metal be $X_2O_3$ . The balanced equation for the reaction is given by:

$X_2O_3+3CO\rightarrow 3CO_2+2X$

8 0

3 years ago

The human body excretes nitrogen in the form of urea, NH₂CONH₂. The key step in its biochemical formation is the reaction of wat

Misha Larkins [42]

Mass perventage of nitrogen in urea, arginine, ornithine is 46.67%, 32.2%,21% respectively.

What is Mass perventage ?

Mass percentage is one way of representing the concentration of an element in a compound or a component in a mixture. Mass percentage is calculated as the mass of a component divided by the total mass of the mixture, multiplied by 100.

Molecular mass of urea (NH2CONH2) is= 2× (Atomic mass of N ) + 4 × (Atomic mass of H) + (Atomic mass of C) (Atomic mass of O) = 60

Mass percentage of N = $Total mass of N atoms in the compoundMass of compound×100=2860×100=46.67%$

chemical formula for arginine is C6H14N4O2

molar mass of C6H14N4O2=174g/mol

moles of N atoms in C6H14N4O2=4

mass of N atoms=14*4=56g

mass percent of N in C6H14N4O2=(56/174)*100=32.2%

the chemical formula for ornithine is C5H12N2O2

molar mass of C5H12N2O2=132g/mol

moles of N atoms in C5H12N2O2=2

mass of N atoms in C5H12N2O2=2*14=28

mass percent of N in C5H12N2O2=(28/132)*100=21%

To learn more about urea click on the link below:

brainly.com/question/17812875

#SPJ4

7 0

1 year ago

The gas in a sealed container has an absolute pressure of 125.4 kilopascals. If the air around the container is at a pressure of

AlexFokin [52]

Answer: C. 25.6 kPa

Explanation:

The Gauge pressure is defined as the amount of pressure in a fluid that exceeds the amount of pressure in the atmosphere.

As such, the formula will be,

PG = PT – PA

Where,

PG is Gauge Pressure

PT is Absolute Pressure

PA is Atmospheric Pressure

Inputted in the formula,

PG = 125.4 - 99.8

PG = 25.6 kPa

The gauge pressure inside the container is 25.6kPa which is option C.

4 0

3 years ago

Identify the variables in this hypothesis.

Zanzabum

Answer:

AJJJJJJJJJJJJJJ

Explanation:

5 0

3 years ago

Read 2 more answers

Which force is most responsible for slowing a bicycle down when the brakes are applied

Leya [2.2K]

Friction <span>is most responsible for slowing a bicycle down when the brakes are applied</span>

7 0

3 years ago