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3 years ago

II need this asap !!!!!!!

Chemistry

1 answer:

Xelga [282]3 years ago

7 0

Answer:

1. B.10 mol/l

2. D.

3.A.

Explanation:

Totoo po yan ganyan po yong sakin

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The pressure of a 250 mL sample of gas is 105 kPa. What would be the pressure if the volume were increased to 375 ml?

Arte-miy333 [17]

Answer:

<h2>The answer is 70 kPa</h2>

Explanation:

In order to find the pressure if the volume were increased to 375 ml we use Boyle's law

That's

$P_1V_1 = P_2V_2$

where

P1 is the initial pressure

P2 is the final pressure

V1 is the initial volume

V2 is the final volume

Since we are finding the final pressure

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

From the question

P1 = 105 kPa = 105 , 000 Pa

V1 = 250 mL

V2 = 375 mL

So we have

$P_2 = \frac{105000 \times 250}{375} = \frac{26250000}{375} \\ = 70000$

We have the final answer as

Hope this helps you

8 0

4 years ago

When hydrochloric acid is poured over potassium sulfide, 43.7 mLmL of hydrogen sulfide gas is produced at a pressure of 758 torr

kvasek [131]

Answer:

0.196 grams of K2S reacted

Explanation:

When hydrochloric acid is poured over potassium sulfide, 43.7 mLmL of hydrogen sulfide gas is produced at a pressure of 758 torrtorr and 26.0 ∘C

How much potassium sulfide has reacted in grams?

Step 1: Data given

Volume of hydrogen sulfide (H2S) produced = 43.7 mL

Pressure = 758 torr = 758/760 = 0.9973684 atm

Temperature = 26.0 °C = 273 + 26 = 299 K

Step 2: The balanced equation

2 HCl + K2S → H2S + 2 KCl

Step 3: Calculate moles H2S

p*V = nRT

n = (pV)/(RT)

⇒ with n= the number of moles of H2S

⇒ with p = the pressure = 0.9973684 atm

⇒ with V = the volume of the gas = 43.7 mL = 0.0437 L

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

⇒ with T = The temperature = 26°C = 299 Kelvin

n = (0.9973684 * 0.0437)/ (0.08206*299)

n = 0.001776 moles H2S

Step 4: calculate moles of K2S

For 2 moles HCl we need 1 mol K2S to produce 1 mol H2S and 2 moles KCl

For 0.001776 moles H2S produced, we need 0.001776 moles K2S

Step 5: Calculate mass of K2S

Mass K2S = moles K2S * molar mass K2S

Mass K2S = 0.001776 moles * 110.26 g/mol

Mass K2S = 0.196 grams K2S

0.196 grams of K2S reacted

6 0

3 years ago

When converting from kilometers to meters, the decimal is moved _______.

Ber [7]

C) 3 places to the right

Metric units:
• Kilo - 1000 units
• Hecto - 100 units
• Deka - 10 units
• Standard Unit
• Deci - 0.1 unit
• Centi - 0.01 unit
• Milli - 0.001 unit

6 0

3 years ago

Allison needs 18 liters of a 5% saline solution. She has a 1% solution and a 10% solution available. How many liters of the 1% s

kolezko [41]

Answer:

10 liters of the 1% solution and 8 liters of the 10% solution she should mix to make the 5% solution.

Explanation:

Let the volume of 1% acid solution used to make the mixture = x L

So, the volume of 10% acid solution used to make the mixture = y L

Total volume of the mixture = <u>x + y = 18 L .................. (1)</u>

For 1% acid solution:

C₁ = 1% , V₁ = x L

For 10% acid solution :

C₂ = 10% , V₂ = y L

For the resultant solution of sulfuric acid:

C₃ = 5% , V₃ = 18 L

Using

C₁V₁ + C₂V₂ = C₃V₃

1×x + 10×y = 5×18

So,

<u>x + 10y = 90 .................. (2)</u>

Solving 1 and 2 we get,

Thus,

<u>10 liters of the 1% solution and 8 liters of the 10% solution she should mix to make the 5% solution.</u>

7 0

3 years ago

Sodium aton has lower electron affinity than chlorine atom why

Citrus2011 [14]

Electron affinity is the energy released when an electron is accepted by a neutral atom forming a negative ion. Chlorine has the higher electron affinity because it readily accepts an electron to become more stable. On the other hand, sodium have to give up an electron to complete its valence shell.

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3 years ago