What mass of
sucrosse, c12h22o11, is needed to
make 500ml of a 0.20 m solution?

34.23 g

Explanation:

Molarity -

Molarity of a substance , is the number of moles present in a liter of solution .

M = n / V

M = molarity

V = volume of solution in liter ,

n = moles of solute ,

Moles is denoted by given mass divided by the molecular mass ,

Hence ,

n = w / m

n = moles ,

w = given mass ,

m = molecular mass .

From the question ,

M = 0.20 M

V = 500mL

Since,

1 L = 1000mL

1 mL = 0.001L

V = 500 mL = 0.5 L

Using the above formula moles can be calculated as -

M = n / V

0.20 M = n / 0.5 L

n = 0.1 mol

The mass of sucrose can be calculated as -

n = w / m

n = 0.1 mol

m ( for sucrose ) = 342.3 g/mol

0.1 mol = w / 342.3 g/mol

w = 34.23 g

16

explanation:

the marks go by 4s

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.