When 1 carbon atom combines with 2 oxygen atoms, the resulting substance is called a

Which of the procedures, if either, is more accurate when making a 1/501/50 dilution of a solution? Transfer 1 mL1 mL with a pip

nikitadnepr [17]

Full question:

First of all, bear in mind that this question is incomplete. Here is the full question:

Which of the procedures, if either, is more accurate when making a 1/50 dilution of a solution?

a) Transfer 1 mL with a pipet into a 50-mL volumetric flask.

b) Transfer 20 mL with a pipet into a 1-L volumetric flask.

c) Both procedures have the same accuracy.

How can the accuracy of either procedure be improved?

a) Use an Erlenmeyer flask instead of a volumetric flask.

b) Use a graduated cylinder instead of a pipet for the transfer.

c) Calibrate each piece of glassware.

d) Instead of using a 1/50 dilution to make the solution, weigh out the material on a balance and transfer ir directly to the volumetric flask.

Answer:

1) c) Both procedures have the same accuracy.

2) c) Calibrate each piece of glassware.

Explanation:

1) Given that the 1/50 relation is maintained whether we pour 1 mL into a 50-mL volumetric flask or we transfer 20 mL with a pipet into a 1-L volumetric flask, both procedures have the same accuracy (because in both procedures we are using volumetric glassware).

When we want the most exact result possible, we need to calibrate the volumetric glassware used (bear in mind that the only volumetric glassware is the buret, the volumetric flask, the micropipet and the pipet). This is usually done measuring the mass of water poured by the recipient or contained in it, and using the density of that liquid to convert mass into volume. In this way is possible, for example, to determine that a pipet poured 10.016 mL and not 10.000 mL.

3 0

3 years ago

Where did the lighter elements like hydrogen and helium go to when the solar system formed

Veronika [31]

<span>Some of them remained in space, some ended up in the gas giants, Jupiter, Saturn, etc. A good percentage ended up in the sun</span>

4 0

4 years ago

1. To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 4.8-L bulb, then fil

Delvig [45]

Answer:

1) The diometic gas is N2 (molar mass 28 g/mol)

2) The partialpressure of oxygen is 316.6 mmHg

Explanation:

Step 1: Data given

Volume = 4.8 L

pressure = 1.60 atm

temperature = 30.0°C

Difference in mass after weighting again = 8.7 grams

Step 2:

PV = nRT

⇒ with P = the pressure of the gas = 1.60 atm

⇒ with V = the volume of the gas = 4.8 L

⇒ with n = the number of moles = mass/molar mass

⇒ with R = the gas constant = 0.08206 L*atm/k*mol

⇒ with T = the temperature = 30.0 °C = 303 K

(1.60 atm) (4.8L) = (n)*(0.08206)*(303 K)

n = (1.60 * 4.8) / ( 0.08206*303)

n = 0.30888 mol

Step 3: Calculate molar mass

Molar mass = mass / moles

Molar mass = 8.7 grams / 0.3089 moles

Molar mass ≈ 28 g/mol

The diometic gas is N2

2) What is the partial pressure of oxygen in the mixture if the total pressure is 545mmHg ?

Step 1: Calculate mass of nitrogen

Let's assume a 100 gram sample. This means 38.8 grams is nitrogen

Step2: Calculate moles of N2

Moles N2 = mass N2 / molar mass N2

Moles N2 = 38.8 grams / 28 .02 grams

Moles N2 = 1.38 moles

Step 3: Calculate moles of O2

Moles O2 = (100 - 38.8)/ 32 g/mol

Moles O2 = 1.9125 moles O2

Step 4: Calculate molefraction of oxygen

Molefraction O2 = moles of component/total moles in mixture

=1.9125/(1.9125 + 1.38 moles)

=0.581

Step 5: Calculate the partial pressure of oxygen

PO2 =molefraction O2 * Ptotal

=0.581 * 545mmHg

=316.6 mmHg

The partialpressure of oxygen is 316.6 mmHg

7 0

3 years ago

Melting ice off a windshield is which change

Marianna [84]

Answer:

Physical Change

Explanation:

The ice isn't changing what it is, because its still water (even though its in a different form) If you freeze it again it will be exactly the same and so its a Physical Change

8 0

3 years ago

Read 2 more answers

Calculate the silver ion concentration in a saturated solution of silver(I) sulfate (K sp = 1.4 × 10 –5). 1.5 × 10–2 M 1.4 × 10–

spin [16.1K]

Answer:

3.0x10⁻²M

Explanation:

Silver sulfate, Ag₂SO₄, has a product constant solubility equilbrium of:

Ag₂SO₄(s) ⇄ 2Ag⁺ + SO₄²⁻

When an excess of silver sulfate is added, some Ag₂SO₄ will react producing Ag⁺ and SO₄²⁻ until reach the equilbrium determined for the formula:

ksp = 1.4x10⁻⁵ = [Ag⁺]² [SO₄²⁻]

Assuming the Ag₂SO₄ that react until reach equilibrium is X, we can replace in Ksp expression:

1.4x10⁻⁵ = [Ag⁺]² [SO₄²⁻]

1.4x10⁻⁵ = [2X]² [X]

1.4x10⁻⁵ = 4X³

3.5x10⁻⁶ = X³

0.015 = X

As [Ag⁺] is 2X:

[Ag⁺] = 0.030 = 3.0x10⁻²M

The answer is:

7 0

3 years ago