1. What is the molality of a solution in which 0.135 moles of CO2 is dissolved in 490mL of water? (1kg of water = 1L of water)

2. What is the molality of a solution in which 23g of NaCl are dissolved in 250g of water?

3. How many moles of HC1 are needed to prepare a 3m (3molal) solution with 1.5Kg of water?

there all right good

explanation:

a electronegativity decreases beacuse the size of nucleus is bigger.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.