Answer:
0.087 moles of water
Explanation:
Given data:
Number of molecules of water = 5.24×10²² molecules
Number of moles of water = ?
Solution:
The given problem will solve by using Avogadro number.
1 mole = 6.022 × 10²³ molecules of water
5.24×10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.87×10⁻¹ mol
0.087 mol
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.
 
        
             
        
        
        
I don't know about 14, but 15 is (4), because a liquid draws in heat to turn into a gas. 16 is (2), because to turn into a cold solid, something has to release heat.
        
             
        
        
        
The given question is incomplete. The complete question is as follows.
A solution contains an unknown mass of dissolved barium ions. When sodium sulfate is added to the solution, a white precipitate forms. The precipitate is filtered and dried and then found to have a mass of 212 mg. What mass of barium was in the original solution? (Assume that all of the barium was precipitated out of solution by the reaction.)
Explanation:
When  and
 and  are added  then white precipitate forms. And, reaction equation for this is as follows.
 are added  then white precipitate forms. And, reaction equation for this is as follows.
         
It is given that mass (m) is 212 mg or 0.212 g (as 1 g = 1000 mg). Molecular weight of  is 233.43.
 is 233.43.
Now, we will calculate the number of moles as follows.
   No. of moles = mass × M.W 
                         = 
                         = 0.00091 mol of  
Hence, it means that 0.00091 mol of  . Now, we will calculate the mass as follows.
. Now, we will calculate the mass as follows.
        Mass = moles × MW 
                  =  
 
                  = 0.124 grams or 124 mg of barium
Thus, we can conclude that mass of barium into the original solution is 124 mg.
 
        
             
        
        
        
Carbohydrates are used for short term energy so it’s gonna be supply energy to the cell, proteins are used for genetic information and building muscles 
 
        
                    
             
        
        
        
When traveling through a smoke-filled area, a person must be able to have distance of at least 4 feet in order to safely reach a fire exit. That is option C.
<h3>What is a smoke-filled area?</h3>
Smoke-filled area is an enclosed area that is filled with smoke gas that is usually made up of carbon monoxide.
The smoke-filled area is usually caused by 
- Burning of plastics or chemical products
When there is smoke-filled area die to fire out break, there are some guidelines to follow to safely reach the fire exit early enough.
The importance of these guidelines include the following:
- enable rescuers to navigate a scene more quickly,
- identify risks and hazards,
- determine the safest way in and out of a building, and 
- map out evacuation routes.
The affected individual should get down and crawl while taking short breath through the nose because cleaner air is nearest to the floor.
Learn more about distance here:
brainly.com/question/7243416
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