Which two solutions, when mixed together, will undergo a double replacement reaction and form a white, solid substance?
1. NaCl(aq) and LiNO3(aq)
2. KCl(aq) and AgNO3(aq)  answer
3. KCl(aq) and LiCL(aq)
4. NaNO3(aq) and AgNO3(aq)
2 is the answer because AgCl is formed and that is a white ppt. 
 
        
                    
             
        
        
        
Answer:
m = 4.7 μg
Explanation:
Given data:
density of acetone = 60.0  μg/L
Volume = 79.0 mL
Mass = ?
Solution:
Formula:
d = m/v
v = 79.0 mL × 1L /1000 mL
v = 0.079 L
Now we will put the values on formula:
d = m/v
60.0  μg/L = m/0.079 L
m = 60.0 μg/L × 0.079 L
m = 4.7 μg
So health risk limit for acetone = 4.7  μg
 
        
             
        
        
        
Answer:
D) both a and c are correct
Explanation:
The reaction rate is a measure of the speed of a chemical reaction. The factors that affects the rate of a chemical reaction are itemised below: 
- Nature of the reactants
- Concentration of the reactants or pressure(if gaseous)
- Temperature
- Presence of catalyst
- Sunlight
Our concern here is temperature. Temperature affects a reaction considerably. Average kinetic energy is directly proportional to the temperature of the reacting particles. When the temperature of a reacting system is increase, the frequency of ordinary and effective collisions per unit time increases. A decrease in temperature implies that the number of collisions also decreases. 
 
        
             
        
        
        
Answer:
vHe / vNe = 2.24
Explanation:
To obtain the velocity of an ideal gas you must use the formula:
v = √3RT / √M
Where R is gas constant (8.314 kgm²/s²molK); T is temperature and M is molar mass of the gas (4x10⁻³kg/mol for helium and 20,18x10⁻³ kg/mol for neon). Thus:
vHe = √3×8.314 kgm²/s²molK×T / √4x10⁻³kg/mol
vNe = √3×8.314 kgm²/s²molK×T / √20.18x10⁻³kg/mol
The ratio is:
vHe / vNe = √3×8.314 kgm²/s²molK×T / √4x10⁻³kg/mol / √3×8.314 kgm²/s²molK×T / √20.18x10⁻³kg/mol
vHe / vNe = √20.18x10⁻³kg/mol / √4x10⁻³kg/mol
<em>vHe / vNe = 2.24</em>
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I hope it helps!
 
        
             
        
        
        
The answer is 3/4.
The coefficient next to each reactant represents the amount of moles. The compound for oxygen is O2 and the compound for aluminum is 4. We can see that the number next to O2 is 3 and the number next to aluminum is 4.