Answer:0,25 g/cm3 creo
Explanation:densidad es masa entre volumen
The person above me is correct I took a test on this so it’s the right answer
Answer:
See explanation below
Explanation:
The melting point (the temperature that it changes from solid to liquid) of a pure substance depends on its mass, the forces between its molecules, and the pressure of the system.
The melting point, or the freezing point, of a mixture, is a temperature between the melting point of its components. Salt has a huge negative melting point, so when it is added to the water, the melting point decreases from 0ºC to -21ºC approximately.
So, the water will only freeze again if the temperature becomes below -21ºC which is very difficult to happen.
Answer:
6 x 10⁵ kg Hg
Explanation:
The mass of mercury in the entire lake is found by multiplying the concentration of the mercury by the volume of the lake.
The volume of the lake is calculated in cubic feet:
V = (SA)x(depth) = (100mi²)(5280ft/mi)² x (20ft) = 5.57568 x 10¹⁰ ft³
Cubic feet are then converted to mL (1cm³=1mL)
(5.57568 x 10¹⁰ ft³) x (12in/ft)³ x (2.54cm/in)³ = 1.578856752 x 10¹⁵ mL
The mass of mercury is then found:
m = CV = (0.4μg/mL)(1g/10⁶μg)(1kg/1000g) x (1.578856752 x 10¹⁵ mL) = 6 x 10⁵ kg Hg
Molality can be expressed by moles of solute over
kilograms of solvent. The question asks the molality of 0.25m NaCl. 0.25m NaCl
is equal to 0.25 moles of NaCl over 1 kg of water.
