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3 years ago

Which lab safety rule do you think is the most important to follow in chemistry lab?

Chemistry

1 answer:

Flauer [41]3 years ago

7 0

Answer:

Practice good personal hygiene. Wash your hands after removing gloves, before leaving the laboratory, and after handling a potentially hazardous material. While working in the laboratory, wear personal protective equipment - eye protection, gloves, laboratory coat - as directed by your supervisor.

Explanation:

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Part 1: A cylinder containing 20.0 L of compressed nitrogen is connected to an empty (evacuated) vessel with an unknown volume.

baherus [9]

Answer:

The volume of the vessel is 250 L

Partial pressure of hydrogen = 189 torr

Explanation:

Using Boyle's law

${P_1}\times {V_1}={P_2}\times {V_2}$

Given ,

V₁ = 20.0 L

V₂ = ?

P₁ = 25 atm

P₂ = 2 atm

Using above equation as:

${P_1}\times {V_1}={P_2}\times {V_2}$

${25}\times {20.0}={2}\times {V_2}$

${V_2}=\frac {{25}\times {20.0}}{2}\ L$

${V_2}=250\ L$

The volume of the vessel is 250 L.

According to Dalton's law of partial pressure:-

$P_{H_2}=Mole\ fraction\times Total\ Pressure$

So, according to definition of mole fraction:

$Mole\ fraction\ of\ H_2=\frac {n_{H_2}}{n_{H_2}+n_{He}}$

Also,

Mole fraction of H₂ = 1 - Mole fraction of He = 1 - 0.75 = 0.25

So,

Total pressure = 756 torr

Thus,

$P_{H_2}=0.25\times 756\ torr$

Partial pressure of hydrogen = 189 torr.

7 0

3 years ago

Which statement describes two organ systems working together to get rid of wastes made by cells?

saw5 [17]

Answer:C

Explanation:it gets rid of waste

8 0

2 years ago

Black coffee has a pH of around 5. Since pH and pOH have an inverse relationship, black coffee has a pOH of ___.

Anon25 [30]

Answer:

pOH = 9.

Explanation:

The inverse relationship between the pH and pOH of any given solution can be written as:

pH = 14 - pOH

Or conversely:

pOH = 14 - pH

With the above information in mind we can use the given pH to calculate the pOH:

pOH = 14 - pH

pOH = 14 - 5

pOH = 9

Thus, black coffee has a pOH of 9.

5 0

3 years ago

Solid iron(II) oxide reacts with oxygen gas to produce solid iron(III) oxide. Balance the equation for this reaction (in lowest

oksian1 [2.3K]

Answer

Hello

I think the reaction is like this FeO+OFe²O³

And the balance reaction is 2Fe+OFe²O³

Explanation:

At first we should find sth that has more atoms than the other then for example we realized that we have two atoms of Fe in Fe²O³ then put 2 before FeO and now we have 2 atoms of Fe in right side and 2 atoms of Fe in left then Oxygen in FeO change to 2 atoms of Oxygen and we have an other one in right side that they become 3 atoms of Oxygen and now we have 3 atoms of Oxygen in both right and left side.

Finally our reaction balanced.

Good luck

6 0

2 years ago

3. Suppose you had titrated your vinegar sample with barium hydroxide instead of sodium hydroxide:

charle [14.2K]

Answer:

39.6 mL

Explanation:

Step 1: Write the balanced neutralization reaction

Ba(OH)₂(aq) + 2 CH₃COOH(aq) ⟶ Ba(CH₃COO)₂(aq) + 2 H₂O(l)

Step 2: Calculate the moles corresponding to 2.78 g of CH₃COOH

The molar mass of CH₃COOH is 60.05 g/mol.

2.78 g × 1 mol/60.05 g = 0.0463 mol

Step 3: Calculate the moles of Ba(OH)₂ needed to react with 0.0463 moles of CH₃COOH

The molar ratio of Ba(OH)₂ to CH₃COOH is 1:2. The moles of Ba(OH)₂ needed are 1/2 × 0.0463 mol = 0.0232 mol.

Step 4: Calculate the volume of 0.586 M solution that contains 0.0232 moles of Ba(OH)₂

0.0232 mol × 1 L/0.586 mol = 0.0396 L = 39.6 mL

6 0

2 years ago