Answer:
105
Explanation:
Density = mass/volume
therefore volume = mass/density
826/7.9=105 (To three significant figure)
 
        
             
        
        
        
Given:
Concentration of Fluoride ions = 0.100 M
Concentration of Hydrogen Fluoride = 0.126 M
Asked: Concentration of fluoride ions after the addition of 5ml of 0.0100 M HCl to 25 mL of the solution
Assume: 50:50 ratio of fluoride ions and HF
12.5ml*0.1mol/L *1L/1000mL + 12.5*0.126mol/L * 1L/1000mL = 2.825x10^-3 moles F-
5ml * 0.01 mol/L *1L/1000mL = 5x10^-5 moles
Assume: Volume additive
Final concentration = 2.825x10^-3 + 5x10^-5 moles/ 30 ml * 1000ml/L =0.0958 M
<span />
        
             
        
        
        
Answer:
it goes to a solid to a liquid
Explanation:
When something is a solid the molecules are impact together and have a small sense of vibration. But as the solid melts away for example ice, the molecules become more loose forming into a liquid
 
        
                    
             
        
        
        
The answer is the 3rd choice