Answer:
Carbon Dioxide fire extinguishers extinguish fire by taking away the oxygen element of the fire triangle and also be removing the heat with a very cold discharge. Carbon dioxide can be used on Class B & C fires. They are usually ineffective on Class A fires
 
        
                    
             
        
        
        
Answer: Sodium + water → hydrogen gas + sodium hydroxide (aq) + heat [(aq) means “dissolved in water”. It stands for “aqueous”.] If we boil off the water, we will be able to see the sodium hydroxide crystals. The sodium hydroxide is one of the two new substances produced by this chemical change.
 
        
             
        
        
        
<u>Answer:</u> The concentration of  comes out to be 0.16 M.
 comes out to be 0.16 M.
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
 are the n-factor, molarity and volume of acid which is
 are the n-factor, molarity and volume of acid which is 
 are the n-factor, molarity and volume of base which is NaOH.
 are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

Hence, the concentration of  comes out to be 0.1862 M.
 comes out to be 0.1862 M.
 
        
             
        
        
        
Answer: 3.7 x10−6 Mole per dm^3
Explanation:
pH is the negative logarithm of hydrogen ion concentration in a solution.
So, pH = - log(H+)
Since the solution has a pH of 5.43
5.43 = -log(H+)
To get hydrogen ion concentration, find the Antilog of 5.43
 (H+) = Antilog (-5.43)
(H+) = 0.000003715
Then, 0.000003715 in standard form becomes 3.7 x10−6 M
Thus, the concentration of hydrogen ion in the solution is 3.7 x10−6 Mole per dm^3