How can I write ecology in my own words for a definition

Two gas-containers, A and B, are connected with a valve. The first container, A, has a volume of 135 mL, and the second containe

stiv31 [10]

Answer:

85.5 mmHg is the pressure of the gas sample when the valve is opened.

Explanation:

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1$ = initial pressure of gas in container A = 165 mmHg

$P_2$ = final pressure of gas = ?

$V_1$ = initial volume of gas in container A= $135 mL$

$V_2$ = final volume of gas = 135 mL + 117 mL = 252 mL

$T_1$ = initial temperature of gas in container A = $22.5^oC=273+22.5=295.5 K$

$T_2$ = final temperature of gas = $12.7^oC=273+12.7=285.7K$

Now put all the given values in the above equation, we get:

$P_2=\frac{P_1V_1\times T_2}{T_1\times V_2}$

$=\frac{165 mmHg\times 135 mL\times 285.7 K}{295.5 K\times 252 mL}$

$P_2=85.5 mmHg$

85.5 mmHg is the pressure of the gas sample when the valve is opened.

8 0

4 years ago

How is filtration done? What is the difference between residue and filtrate?

LiRa [457]

Answer:

residue is whatever remains after something else has been removed while filtrate is the liquid or solution that has passed through a filter, and which has been separated from the filtride.

filtration id done by placing a filter paper on the beaker or container then pour the filtride then let it settle and it will pass through and you will have the fitrate and residue

Explanation:

3 0

3 years ago

A chemist heats the block of copper as shown in the interactive, then places the metal sample in a cup of oil at 25.00 °C instea

Mazyrski [523]

When the oil is added to the heated copper, the energy in the system is

conserved.

The mass of the oil in the cup, is approximately 64.73 grams.

Reasons:

The question parameters are;

Temperature of the oil in the cup = 25.00°C

Final temperature of the oil and copper, T₂ = 27.33 °C

Specific heat of copper, c₂ = 0.387 J/(g·°C)

Specific heat capacity of oil, c₁ = 1.74 J/(g·°C)

Required:

The mass of oil in the cup.

Solution:

The mass of the copper, m₂ = 17.920 g

Temperature of copper after heating, T₂ = 65.17°C

Temperature of the copper after being placed in the cup of oil, T₂ = 27.33°C

Heat lost by copper = Heat gained by the oil

m₂·c₂·(T₂ - T₃) = m₁·c₁·(T₃ - T₁)

Therefore, we get;

17.920 × 0.387 × (65.17 - 27.33) = m₁ × 1.74 × (27.33 - 25)

262.4219136 = 4.0542·m₁

m₁ ≈ 64.73

The mass of the oil in the cup, m₁ ≈ 64.73 g

Learn more here:

brainly.com/question/21406849

Possible part of the question obtained from a similar question online, are;

The mass of the copper, m₂ = 17.920 g

Temperature of copper after heating = 65.17°C

6 0

3 years ago

Preparation of Standard Buffer for Calibration of a pH Meter The glass electrode used in commercial pH meters gives an electrica

lana66690 [7]

Answer:

Mass of NaH₂PO₄·H₂O = 8.542 g
Mass of Na₂HPO₄ = 5.410 g

Explanation:

Keeping in mind the equilibrium:

H₂PO₄⁻ ↔ HPO₄⁻² + H⁺

We use the Henderson-Hasselbalch equation (H-H):

pH = pka + $log\frac{[A^{-}]}{[HA]}$

For this problem [A⁻] = [HPO₄⁻²] and [HA] = [H₂PO₄⁻]

From literature we know that pka = 7.21, from the problem we know that pH=7.00 and that

[HPO₄⁻²] + [H₂PO₄⁻] = 0.100 M

From this equation we can express [H₂PO₄⁻] in terms of [HPO₄⁻²]:

[H₂PO₄⁻] = 0.100 M - [HPO₄⁻²]

And then replace [H₂PO₄⁻] in the H-H equation, in order to calculate [HPO₄⁻²]:

$7.00=7.21+log\frac{[HPO4^{-2}] }{0.100 M-[HPO4^{-2}]} \\-0.21=log\frac{[HPO4^{-2}] }{0.100 M-[HPO4^{-2}]}\\10^{-0.21} =\frac{[HPO4^{-2}] }{0.100 M-[HPO4^{-2}]}\\0.616*(0.100M-[HPO4^{-2}])=[HPO4^{-2}]\\0.0616 M = 1.616*[HPO4^{-2}]\\0.03812 M =[HPO4^{-2}]$

With the value of [H₂PO₄⁻], we calculate [HPO₄⁻²]:

[HPO₄⁻²] + 0.0381 M = 0.100 M

[HPO₄⁻²] = 0.0619 M

Finally, using the concentrations, the volume, and the molecular weights; we can calculate the weight of each substance:

Mass of NaH₂PO₄·H₂O = 0.0619 M * 1 L * 138 g/mol = 8.542 g

Mass of Na₂HPO₄ = 0.0381 M * 1 L * 142 g/mol = 5.410 g

8 0

4 years ago

WILL GIVE BRAINLIEST IF YOU EXPLAIN (this is 7th grade Science / Chemistry btw):

alekssr [168]

Answer:

2 chlorine atoms.

Explanation:

H₂ + Cl₂ → 2HCl

The Law of Conservation of Mass states that matter can neither be created nor destroyed in a chemical reaction.

If 2 molecules of Hydrogen and 2 molecules of Chlorine is present in the reactants, the same no. of atoms should also be present in the product.

∴ the no. of chlorine atoms in the product is 2.

8 0

3 years ago

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