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3 years ago

Please, I need at least accurate answers for my Sound Knowledge Check for my Science class.

Chemistry

2 answers:

mrs_skeptik [129]3 years ago

8 0

Pretty sure it’s absorption

Alla [95]3 years ago

5 0

Answer:

1.A

2.A

3.C

4.C

5.B

6.A

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A student was given four unknown solutions. Each solution was checked for. conductivity and tested with. phenolphthalein. The re

777dan777 [17]

Answer: (3) C

Explanation:

4 0

2 years ago

the pressure and temperature of 10 liters of gas are doubled. if the original condition are 2 atmosphere of pressure and 400k wh

Harman [31]

Answer:

$\boxed{\text{10 L}}$

Explanation:

We have two pressures, two temperatures, and one volume.

This looks like a question in which we can use the Combined Gas Law to calculate the volume.

$\dfrac{p_{1}V_{1}}{T_{1}} = \dfrac{p_{2}V_{2} }{T_{2}}$

Data:

$\begin{array}{rclrclrcl}p_{1}& =& \text{2 atm}\qquad & V_{1} &= & \text{10 L}\qquad & T_{2}& =& \text{400 K}\\p_{2}& =& \text{4 atm}\qquad & V_{2} &= & \text{?}\qquad & T_{2}& =& \text{800 K}\\\end{array}$

Calculation:

$\begin{array}{rcl}\dfrac{2 \times 10}{400}& =& \dfrac{4V_{2} }{800}\\\\0.050& = &0.0050V_{2}\\V_{2}& = &\mathbf{10 L}\end{array}\\\text{The final volume is }\boxed{\textbf{10 L}}$

4 0

3 years ago

Fritz Haber, a German chemist, discovered a way to synthesize ammonia gas (NH3) by combining hydrogen and nitrogen gases accordi

Westkost [7]

1) Write the balanced equation to state the molar ratios:

<span>3H2(g) + N2(g) → 2NH3(g)

=> molar ratios = 3 mol H2 : 1 mol N2 : 2 mol NH3

What volume of nitrogen is needed to produce 250.0 L of ammonia gas at STP?

First, convert the 250.0 L of NH3 to number of moles at STP .

Use the fact that 1 mole of gas at STP occupies 22.4 L

=> 250.0 L * 1mol/22.4 L = 11.16 L

Second, use the molar ratio to find the number of moles of N2 that produces 11.16 L of NH3

=> 11.16 L NH3 * [1 mol N2 / 2 mol NH3] = 5.58 mol N2

Third, convert 5.58 mol N2 into liters at STP

=> 5.58 mol N2 * [22.4 L/mol] = 124.99 liters

Answer: 124,99 liters

What volume of hydrogen is needed to produce 2.50 mol NH3 at STP?

First, find the number of moles of H2 that produce 2.50 mol by using the molar ratios:

2.50 mol NH3 * [3mol H2 / 2 mol NH3] = 3.75 mol H2

Second, convert the number of moles to liters of gas at STP:

3.75 mol * 22.4 L/mol = 84 liters of H2

Answer: 84 liters

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6 0

3 years ago

Read 2 more answers

I'm not really sure on how to test if it is a chemical or physical change....

kolezko [41]

Chemical change because it cannot be reversed

4 0

3 years ago

1. Which of the following is a combination reaction?

DaniilM [7]

Answer:

The answer to your question is: letter A

Explanation:

A combination reaction is when there are two reactants that gives only one product.

a. 2SO2 + O2—> 2SO3 This is a combination reaction,

2 reactants gives one product.

b. Zn + Cu(NO3)2–>Zn(NO3)2 + Cu This is not a combination reaction,

it's a single replacement reaction.

c. 2H2O2–> 2H2O+O2 This is a decomposition reaction

d. AgNO3 + NaCl → AgCl+NaNO3 THis is a double replacement reaction.

8 0

3 years ago