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KatRina [158]
3 years ago
7

What is the only sure evidence for a chemical reaction?

Chemistry
1 answer:
kkurt [141]3 years ago
4 0
Change in colours change in state solid shape smell light no light
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A marine biologist is preparing a deep-sea submersible for a dive. The sub stores breathing air under high pressure in a spheric
Luba_88 [7]

Complete Question

A marine biologist is preparing a deep-sea submersible for a dive. The sub stores breathing air under high pressure in a spherical air tank that measures 74.0 wide. The biologist estimates she will need 2600 L of air for the dive. Calculate the pressure to which this volume of air must be compressed in order to fit into the air tank. Write your answer in atmospheres. Round your answer to significant digits.

Answer:

The pressure required is P_2= 12.2 \ atm

Explanation:

Generally the volume of a sphere is mathematically denoted as

             V_s = \frac{4}{3} * \pi r^3

Substituting r =  \frac{d}{2} = \frac{74}{2} = 37cm

          V_s = \frac{4}{3} * 3.42 * (37)^2

               V_s = 2.121746 *10^5 cm^3

Converting to Liters

               V_s = \frac{2.121746 *10^5}{1000}

                V_s= 212.1746L

Assume that the pressure at which the air is given to the diver is 1 atm when the air was occupying a volume of 2600L

So

From Charles law

               P_1V_1 = P_2 V_s

Substituting  V_1 =2600 L ,   P_1 = 1 atm , V_s  =212.1746L , and making P_2 the subject we have

                 P_2 = \frac{P_1 * V_1}{V_s}

                     = \frac{1 * 2600}{212.1746}

                    P_2= 12.2 atm

               

6 0
3 years ago
Look at the following hypothetical reaction: A+3B-->C+3D
jonny [76]
Not sure why you reposted your question, the answer is D as explained in my other answer.
7 0
4 years ago
Read 2 more answers
How many significant figures does the following number contain: 385.01
dusya [7]

Answer:

5 significant figures

Explanation:

  • Zeros that come before any non-zero digits are never significant.

  • Zeros that are in between any non-zero digits are always significant.

  • Zeros that come after any non-zero digit are ONLY significant if a decimal point in present somewhere in the number. (In this case there is a decimal point, but there aren't any zeros at the end of this number.)

I have underlined the significant figures in this number:

<u>3</u> <u>8</u> <u>5</u> . <u>0</u> <u>1</u>

3 0
4 years ago
1. If you have 25% radioactive parent atoms in a mineral crystal, and 75% daughter atoms, how many half-lives have passed?
Andreyy89
Too freaking many... or maybe not many at all

5 0
3 years ago
In a simplified model of a hydrogen atom, the electron moves around the proton nucleus in a circular orbit of radius 0.53 × x10−
sergiy2304 [10]

the force between the electron and the proton.
a) Use F = k * q1 * q2 / d² 
where k = 8.99e9 N·m²/C² 
and q1 = -1.602e-19 C (electron) 
and q2 = 1.602e-19 C (proton) 
and d = distance between point charges = 0.53e-10 m 
The negative result indicates "attraction". 

the radial acceleration of the electron. 
b) Here, just use F = ma 
where F was found above, and 
m = mass of electron = 9.11e-31kg, if memory serves 
a = radial acceleration 

the speed of the electron. 
c) Now use a = v² / r 
where a was found above 
and r was given 

<span> the period of the circular motion.</span>
d) period T = 2π / ω = 2πr / v 
where v was found above 
and r was given 
3 0
3 years ago
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