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3 years ago

When planning a simple experiment, what does it mean to “test one variable”?

Chemistry

1 answer:

SSSSS [86.1K]3 years ago

3 0

Answer:

I believe the answer is "b". "During the experiment, the scientist has only one element, or variable, that is changed to test the hypothesis."

Explanation:

I remember from last year but I'm not totally sure. Good luck!

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An oxygen atom has a mass of 2.66*10^-23 and a glass of water has a mass of 0.050 kg. What is the mass of 1 mole of oxygen atoms

Nutka1998 [239]

Answer:

16.0 g; 3.1 mol

Explanation:

(a) Mass of O atoms

Mass = 6.022 × 10^23 atoms × (2.66 × 10^-23 g/1 atom) = 16.0 g

(b) Moles of O atoms

0.050 kg = 50 g

Moles = 50 g × (1 mol/16.0 g) = 3.1 mol

4 0

3 years ago

Read 2 more answers

Deduce the charge of Z ,in the compound of ZBr2

lyudmila [28]

Answer:

Explanation:

The charge on Z in the compound ZB₂ is a 2+

From the given compound:

We know that Br is bromine with a charge of -1;

So;

Using the combining power approach:

Atoms Z Br

Combining power 2 1

Exchange of valency 1 2

So;

The charge on Z is 2+

8 0

3 years ago

Separation technique used to separate mud and water without heating

Murrr4er [49]

Answer:

Separation technique used to separate mud and water without heating:

Sedimentation-Decantation

Explanation:

1.The settling of the heavier particle at the bottom when the container is left undisturbed is called sedimentation.

In a mixture of Mud and water :

In this process the heavy mud particles settle at the bottom due to their high density .

2. Decantation : It is the process of pouring out the upper clear layer of the light particles.

In a mixture of Mud and water :

The water is lighter and form a clear layer over the settled mud particles. Hence by decantation the clear water is poured into a clean separate container

Thus mud remain in the bottom and the mixture is separated

8 0

3 years ago

Use the Conductivity interactive to identify each aqueous solution as a strong electrolyte, weak electrolyte, or nonelectrolyte.

Yuliya22 [10]

Explanation:

strong electrolyte- Nacl HCL NAOH

weak electrolyte- c12H22O, NH3

8 0

3 years ago

Assuming steam to be an ideal gas, calculate its specific volume and density at a pressure of 90 lb/in2 and a temperature of 650

Vitek1552 [10]

Answer:

1) Sv = 0.4584 m³/Kg...assuming steam as an ideal gas

% deviation from the values in the steam tables

⇒ % dev = 45 %

2) mass air = 272.617 Kg; assuming air to be an ideal gas

Explanation:

ideal gas:

PV = RTn

molar volume:

⇒ V/n = RT/P

∴ P = 90 psi * ( 0.06895 bar/psi ) = 6.2055 bar

∴ T = 650 F = 343.33 °C = 616.33 K

∴ R = 0.08314 bar.L/mol.K

⇒ V/n = (( 0.08314 )*(616.33 K )) / 6.2055 bar

⇒ V/n = 8.2574 L/mol * ( m³/1000L ) = 8.2574 E-3 m³/mol

specific volume ( Sv ):

∴ Mw = 18.01528 g/mol

⇒ Sv = 8.2574 E-3 m³/mol * ( mol / 18.01528 g ) * ( 1000 g/Kg )

⇒ Sv = 0.4584 m³/Kg

steam table:

∴ P = 6.2055 bar ≅ 6 bar → Sv = 0.3157 m³/Kg

⇒ % deviation = (( 0.4584 - 0.3157 ) / 0.3157) * 100

⇒ % dev = 45.2 %; significant value, assuming steam to be a ideal gas

2) mass air, assuming ideal gas:

∴ V = 20ft * 35ft * 10ft = 7000ft³ * ( 28.3168 L/ft³ ) = 198217.6 L

∴ P = 17 psi * ( 0.06895 bar/psi ) = 1.172 bar

∴ T = 75 °F = 23.89 °C = 296.89 K

∴ R = 0.08314 bar.L/K.mol

⇒ n air = PV/RT = (( 1.172 )*( 198217.6 )) / (( 0.08314 )*( 296.89 ))

⇒ n air = 9411.616 mol air

∴ Mw air = 28.966 g/mol

⇒ mass air = 9411.616 mol * ( 28.966 g/mol ) = 272616.892 g = 272.617 Kg

7 0

3 years ago