The student should set up an experiment in which he will require a crucible, a sample of hydrated copper sulfate (CuSO₄ <span>• 5H</span>₂O), a hot plate and a digital mass balance.
First, the student should check the mass of the empty crucible, then add the sample to the crucible and check the mass again. The difference is the mass of the sample.
Next, the student should place the crucible on a hot plate and begin heating the sample. After regular time intervals, such as two minutes, the students should measure the mass of the crucible and sample and note it down until it stops decreasing.
After a final mass of the sample has been obtained, the student may subtract this from the initial mass and find the mass of water evaporated.
Answer:
The number of molecules = 2.6408 molecules
Explanation:
To determine the number of molecules in water, we need to determine how many moles of water we have
Water has a molar mass of 18.015g/mol, this means that one mole of water molecules has a mass of 18.015g
To find the number of molecules,
7.9g * 1 mole H2O/ 18.015g
= 0.4385mole of H2O
Using avogadro number,
0.4385 H2O * 6.022* 10^23molecules/ 1 mole of H2O
That's 0.4385 H2O multipled by 6.022*10^ 23 molecules divided by 1 mole of H2O
Which gives == 2.6408 molecules
Answer:
d) 41.20 mi/gal.
Explanation:
Initial odometer reading, D1 = 651.1 mi
Final odometer reading, D2 = 1314.4 mi
Volume of gas used = 16.1 gal
Gas mileage = (D2 - D1)/V
= (1314.4 - 651.1)/16.1
= 41.2 mi/gal.
Answer:
When two or more substances, that do not react chemically, are blended together,
the result is a mixture in which each component retains its individual identity and
properties.
The separation of the components of a mixture is a problem frequently encountered
in chemistry. The basis of the separation is the fact that each component has a
different set of physical and chemical properties. The components are pure substances
which are either elements or compounds. Under the same conditions of pressure and
temperature, the properties of every sample of a pure substance are identical. Each
sample melts at the same temperature, boils at the same temperature, has the same
solubility in a given solvent, etc.
<span>disproportionation is a type of redox reaction in which an element can undergo both oxidation and reduction.
Let's take a look at the choices:
First we have the oxide ion. Oxide ion has a charge of -2 which is the lowest charge that an oxygen atom can have. Therefore, an oxide ion cannot be further reduced, so this choice is not correct.
Next we have the peroxide ion. The oxygen has a charge of -1 which means it can be further reduced. So, this choice is acceptable
Last but not least, we have the superoxide ion. The oxygen has a charge of -1/2 which means it can be further reduced. So, this choice is also acceptable.
Based on this, we have two accepted choices which are b and c.</span>