If Sally has 250 grams of cement, how many kilograms does she have? How many milligrams?

A dark purple liquid is diluted by adding water.

alexandr402 [8]

Answer: The process is diffusion.

Explanation:

a dark liquid will have the highest concentration of dark purple atoms/molecules so it gives a concentrated colour.

when water is added to it, the colourless water molecules fill up the gaps between the purple particles and so their colour fades and becomes lighter and lighter as we add more water. see the image attached where imagine the red particles are water and the blue particles are purple particles. thats why the colour fades.

6 0

1 year ago

Question 8 (9 points) Match the lab equipment with its purpose

Deffense [45]

Answer:

$\sf \boxed{4} \mapsto Pipet$

$\sf\boxed{7}\mapsto Test \:tube \: rack$

$\sf\boxed{3}\mapsto Test\: table$

$\sf\boxed{5}\mapsto Scoopula$

$\sf\boxed{1}\mapsto Graduated\: cylinder$

$\sf\boxed{9}\mapsto Bunsen \:burner$

$\sf\boxed{2}\mapsto Beaker$

$\sf \boxed{8}\mapsto Spot\: plate$

$\sf\boxed{6}\mapsto Goggles$

Explanation:

Pipet is used to dispense a very small amount of liquid.

Test tube rack is used to hold multiple test tubes at the same time.

Test Table is used to view chemical reactions or hold or heat small amounts of substance.

Scoopula is used to dispense chemicals from a larger container.

Graduated cylinder is used to measure volume very precisely.

Bunsen burner is used to heat objects.

Beaker is used to transport heat or store substance.

Spot plate is used to observe the color changes of small quantities of a reacting mixture.

Goggles are used to protect the eyes from flying objects or chemical splashes.

_____________________________________________________

7 0

3 years ago

Calculate the number of milliliters of 0.440 M KOH required to precipitate all of the Fe2+ ions in 187 mL of 0.692 M FeSO4 solut

EleoNora [17]

Answer:

588.2 mL

Explanation:

FeSO₄(aq) + 2KOH(aq) → Fe(OH)₂(s) + K₂SO₄(aq)

First we calculate how many Fe⁺² moles reacted, using the given concentration and volume of FeSO₄ solution (the number of FeSO₄ moles is equal to the number of Fe⁺² moles):

moles = molarity * volume

187 mL * 0.692 M = 129.404 mmol Fe⁺²

Then we convert Fe⁺² moles to KOH moles, using the stoichiometric ratios:

129.404 mmol Fe⁺² * $\frac{2mmolKOH}{1mmolFeSO_4}$ = 258.808 mmol KOH

Finally we calculate the required volume of KOH solution, using the given concentration and the calculated moles:

volume = moles / molarity

258.808 mmol KOH / 0.440 M = 588.2 mL

6 0

3 years ago

The volume of air in a person’s lungs is 615 mL at a pressure of 760. mmHg. Inhalation occurs as the pressure in the lungs drops

chubhunter [2.5K]

Answer: The final volume of lungs is 621.5 mL

Explanation:

To calculate the new volume, we use the equation given by Boyle's law. This law states that pressure is inversely proportional to the volume of the gas at constant temperature.

The equation given by this law is:

$P_1V_1=P_2V_2$