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2 years ago

What must astronauts use microphones and headphones in outer space

1 answer:

3 0

In order for sound to be hear, it must travel through a medium, such as air, through which its waves can make a disturbance. In space there is no air, so microphones must be used.

You might be interested in

How many lead (Pb) atoms will be generated when 5.38 moles of ammonia react according to the following equation: 3PbO+2NH3→3Pb+N

jasenka [17]

Answer:

4.86×10^23 molecule of Pb

Explanation:

Based on that equation, for every 2 moles of ammonia, you get 3 moles of lead.

So:

2 mol NH3/ 3 mol Pb

Using this ratio we can find the amounts of either molecule. Given 5.38 mol NH3:

(5.38 NH3)(3 Pb/ 2 NH3) = (5.38)(3/2) mol Pb = 8.07 mol Pb

Then, we just need to use Avagadro's number to get the number of molecules.

(8.07)(6.02×10^23) = 4.86×10^23 molecule of Pb

4 0

2 years ago

Read 2 more answers

A student conducting a calorimetry investigation determines a negative ∆H. What does the negative value indicate about the react

lawyer [7]

Answer:

Explanation:

correct

5 0

2 years ago

Determine the poh of a 0.348 m ba(oh)2 solution at 25°c.

vladimir1956 [14]

Given:

Concentration of Ba(OH)2 = 0.348 M

To determine:

pOH of the above solution

Explanation:

Based on the stoichiometry-

1 mole of Ba(OH)2 is composed of 1 mole of Ba2+ ion and 2 moles of OH- ion

Therefore, concentration of OH- ion = 2*0.348 = 0.696 M

pOH = -log[OH-] = - log[0.696] = 0.157

Ans: pOH of 0.348M Ba(OH)2 is 0.157

6 0

2 years ago

Read 2 more answers

Three solutions contain a certain acid. The first contains 10% acid, the second 30%, and the third 50%. A chemist wishes to use

Fittoniya [83]

Answer:

To prepare 50L of 32% solution you need: 11L of 30% solution, 22L of 50% solution and 17L of 10% solution.

Explanation:

A 32% solution of acid means 32L of acid per 100L of solution. As the chemist wants to make a solution using twice as much of the 50% solution as of the 30% solution it is possible to write:

2x*50% + x*30% + y*10% = 50L*32%

130x + 10y = 1600 (1)

-Where x are volume of 30% solution, 2x volume of 50% solution and y volume of 10% solution-

Also, it is possible to write a formula using the total volume (50L), thus:

2x + x +y = 50L

3x + y = 50L (2)

If you replace (2) in (1):

130x + 10(50-3x) = 1600

100x + 500 = 1600

100x = 1100

x = 11L -Volume of 30% solution-

2x = 22L -Volume of 50% solution-

50L - 22L - 11L = 17 L -Volume of 10% solution-

I hope it helps!

8 0

2 years ago

A solution is prepared by condensing 4.00 l of a gas, measured at 27°c and 748 mmhg pressure, into 58.0 g of benzene. calculate

fgiga [73]

First, we are using the ideal gas law to get n the number of moles:

PV = nRT

when P is the pressure = 748 mmHg/760 = 0.984 atm

V is the volume = 4 L

R is ideal gas constant = 0.0821

T is the temperature in Kelvin = 300 K

∴ n = 0.984atm*4L/0.0821*300

= 0.1598 moles

when the concentration = moles * (1000g / mass)

= 0.1598 * (1000g / 58 g )

= 2.755 M

when the freezing point = 5.5 °C

and Kf = - 5.12 °C/m

∴ the freezing point for the solution = 5.5 °C + (Kf*m)

= 5.5 °C - (5.12°C/m * 2.755m)

= -8.6 °C

8 0

2 years ago