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3 years ago

Please help me with those questions please

Chemistry

1 answer:

lawyer [7]3 years ago

8 0

Answer:

I know the answer to 5, i think

Explanation:

<h2>No, if both parents were left-handed, they would not have to be left-handed</h2>

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A piston has an initial volume of 1.643 L at a pressure of 128 kPa. The temperature is maintained at 27 oC as the volume is decr

aivan3 [116]

Answer:

355 kPa

Explanation:

The ideal gases follow Boyle's law: at constant temperature pressure and volume are inversely related:

$PV=constant$

$P_1V_1=P_2V_2$

$P_2=\dfrac{P_1V_1}{V_2}$

Subsituting and computing:

$P_2=\dfrac{1.643L\times 128kPa}{0.593L}\approx355kPa$

8 0

3 years ago

How would you prepare 250 mL of a 0.100 M solution of fluoride ions from solid CaF2?

andrey2020 [161]

In 250 mL of volumetric flask add 0.975875 grams of $CaF_2$ and dissolve it in the 250 mL of water.

Given:

The solid of calcium fluoride.

To prepare:

The 250 mL solution of 0.100 M of fluoride ions from solid calcium fluoride.

Method:

Molarity of the fluoride ion solution needed = M = 0.100 M

The volume of the fluoride ion solution needed = V = 250 mL

$1 mL = 0.001L\\V=250 mL=250\times 0.001 L=0.250 L$

The moles of fluoride ion needed = n

According to the definition of molarity:

$M=\frac{n}{V}\\0.100M=\frac{n}{0.250 L}\\n=0.100M\times 0.250 L=0.025 mol$

Moles of fluoride ion = 0.025 mol

We know that solid calcium fluoride dissolves in water to give calcium ions and fluoride ions.

$CaF_2(s)\rightarrow Ca^{2+}(aq)+2F^-(aq)$

According to reaction, 2 moles of fluoride ions are obtained from 1 mole of calcium fluoride, then 0.025 moles of fluoride ions will be obtained from:

$=\frac{1}{2}\times 0.025 mol=0.0125 \text{mol of } CaF_2$

Moles of calcium fluoride = 0.0125 mol

Mass of calcium fluoride needed to prepare the solution :

$=0.0125 mol\times 78.07 g/mol=0.975875 g$

Preparation:

Weight 0.975875 grams of calcium fluoride
Add weighed calcium fluoride to a volumetric flask of the labeled volume of 250 mL.
Now add a small amount of water to dissolve the calcium fluoride completely.
After this add more water up to the mark of the volumetric flask of volume 250 mL.

Learn more about molarity of solution ere:

brainly.com/question/10053901?referrer=searchResults

brainly.com/question/10270173?referrer=searchResults

3 0

3 years ago

Atomic fission requires temperatures of one million degrees or hotter. True False

pickupchik [31]

Answer: The correct answer is false.

Explanation:

Atomic fission reactions are defined as reactions in which nucleus of an atom splits into two or more smaller nuclei. These reactions are carried out in nuclear reactors. The temperature range for the reactors are around 300°C.

Atomic fusion reactions are the reactions in which nucleus of two or more atoms fuse together to form one large nuclei. These reactions require a huge amount of energy to occur. The temperature required by these reactions are about one million kelvins.

Hence, the given statement is False.

8 0

3 years ago

Convert 86,000 cm into km

ddd [48]

.86km is the correct answer

3 0

3 years ago

Read 2 more answers

___________ polymers can be produced in large quantities at low cost. please. thank you.

MA_775_DIABLO [31]

Answer:

Plastic polymers

Explanation:

Plastic polymers are usually made up of synthetic and semi-synthetic polymers such as polyethylene, polystyrene etc.

Plastic polymers have a unique property called malleability. Malleability is the ability of a substance to be moulded into different sizes and shapes.

When hear is applied plastics gets soft and can be molded into different forms and then it becomes hardened after exposure to air(dried).

The plastic polymers are usually very cheap to produce in large quantities which is why it is very common in industries.

5 0

3 years ago