Phenolphthalein turn pink in basic solutions.it turn colourless in acid solution.
Hence options(1)is correct
        
                    
             
        
        
        
Organisms are living things. Us humans are also living things, so we are helpful and harmful to other organisms. For example: we can help another human being with something, or we can help a plant/tree grow if we water it. In return, they also help us by providing us with oxygen. however, we can also be harmful to each other and the environment, for example: we can't hurt each other, or plant or animals by killing them or we can hurt insects by stepping on them. Therefore, organisms are helpful and harmful to each other.
        
             
        
        
        
Answer:
44.8 L
Explanation:
Using the ideal gas law equation:
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (K)
At Standard temperature and pressure (STP);
P = 1 atm
T = 273K
Hence, when n = 2moles, the volume of the gas is:
Using PV = nRT
1 × V = 2 × 0.0821 × 273
V = 44.83
V = 44.8 L
 
        
             
        
        
        
Hello there! With the values of density and volume, you would be able to find the object's mass. 
Density is found by dividing the mass by the volume, so you could place in the values of the density and the volume to get the mass.
For example:
500 = mass/10
The 500 being density and 100 being volume. You would use simple math rules and multiply 10 by 500, and you'd get 5000, therefore using the density and volume values and giving you the mass. 
I hope I could help you and have a great day!