What number of moles of O2 will be produced by the decomposition of 4.4 moles of water?

Dana is trying to determine if an unknown sample is a pure substance or not. The sample has a cloudy white color, and it seems e

Firdavs [7]

Answer:

Dana filtered the sample and larger granules of the sample were left behind.

Explanation:

If a substance is pure, it will have a uniform composition throughout. It will not separate into particles of various sizes.

One of the characteristics of pure substances is that they are homogeneous. A mixture is definitely made up of particles of various sizes.

Since the particles was filtered and larger granules were left behind, the sample has been separated by a physical method (filtration). Only a mixture can be separated by physical methods. It is not a pure substance.

5 0

2 years ago

What is the molar mass of an element?

Vesnalui [34]

The answer is: the mass of 6.02 x 1023 representative particles of the element.

The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).

For example, molar mas of ammonia is 17.031 g/mol.

M(NH₃) = Ar(N) + 3 · Ar(H) · g/mol.

M(NH₃) = 14.007 + 3 · 1.008 · g/mol.

M(NH₃) = 17.031 g/mol.

The molar mass (M) is the mass of a given substance (in this example ammonia) divided by the amount of substance.

8 0

3 years ago

The valences of metal x,y and z are 1,2 and 3 respectively. What are the formulae of their;a) hydroxides, b) sulphates, c) hydro

Rina8888 [55]

Answer:

See answer below

Explanation:

AS we know that the valence for those metals X, Y, and Z are 1, 2 and 3, we can determine the formula of each compound.

1. Hydroxides.

An hydroxide is formed when an oxyde of a metal reacts with water. When this happens, the general molecular formula is:

Meₐ(OH)ₙ

Where:

a: valence or charge of the hydroxide (Which is -1)

n: valence of the metal.

Following this, the formula for X, Y and Z would be:

XOH

Y(OH)₂

Z(OH)₃

2. Sulphates

Sulphates follow a similar rule of hydroxide in the general molecular formula, but instead of having a charge of -1, it has a charge of -2 so:

Mₐ(SO₄)ₙ

So, following the rule:

X₂SO₄

Y₂(SO₄)₂ ------> YSO₄

Z₂(SO₄)₃

3. Hydrogens

Following the same rule as the previous, hydrogens works with a charge of -1, so:

MₐHₙ

Then:

XH

YH₂

ZH₃

4. Carbonates.

This follows the same rule as sulphates, with the same charge so:

Mₐ(CO₃)ₙ

Then:

X₂CO₃

YCO₃

Z₂(CO₃)₃

5. Nitrates

Follow the same rule as the hydroxides, with the same charge of -1.

Mₐ(NO₃)ₙ

Then:

XNO₃

Y(NO₃)₂

Z(NO₃)₂

6. Phosphates

In the case of phosphates, these have a charge of -3 so:

Mₐ(PO₄)ₙ

Then:

X₃PO₄

Y₃(PO₄)₂

Z₃(PO₄)₃ ----> ZPO₄

Hope this helps

6 0

2 years ago

Determine the mass of 5.20 moles of c6h12

Gwar [14]

Mass is equal to moles x molar mass, and the molar mass of C6H12 is 84, therefore the mass is 436.8 g, but 437 rounded to correct significant figures

5 0

3 years ago

In the example, the final kinetic energy is determined to be ___________ because at the peak height, the ball instantaneously st

alina1380 [7]

TLDR: The kinetic energy is determined to be zero.

Kinetic energy is energy of motion; when an object is moving (i.e. it has speed or velocity), it has some amount of kinetic energy. The equation itself looks like so:

KE=1/2(m)(v)^2,

where "m" represents the mass of the object and "v" represents the objects speed or velocity. In this example, the ball has stopped, meaning it has no speed/velocity. This means that the final kinetic energy is determined to be zero or none, due to the lack of motion. Mathematically, you can see this by substituting "0" in for "v" (the ball is stopped):

KE=1/2(m)(v)^2

KE=1/2(m)(0)^2

KE=1/2(m)*0

KE=1/2*0

KE=0 J,

or zero kinetic energy.

Hope this helps! :)

7 0

3 years ago

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