The Ozone layers, i think
15.5% by mass is
equivalent 15.5 g urea in 100 g solution or 155 g urea in 1 kg solution. <span>
<span>we know that molality = moles solute / kg solvent
<span>moles solute = 155 g / 60 g/mol = 2.58 moles urea
</span></span></span>
Since there are 155 g
urea in 1000g solution, hence the solvent is 845 g or 0.845 kg
So:<span>
<span>molality = 2.58 / 0.845 = 3.06 m</span></span>
Answer:
I think its called a compound
Explanation:
2 or more different particles is called a compound.
17. ΔH rxn is the enthalpy of a reaction. It is the amount of energy or heat absorbed in a reaction. If enthalpy is positive, it means the reaction absorbs heat, which means it is endothermic. If the enthalpy is negative, it means the reaction release heat, which means it is exothermic.
18. yes, it is possible in theory but it is not necessary. Water is the ideal, cheaper, and most abundant liquid for a calorimeter.
19. Specific heat= heat/mass*Temp. the mass is already known You can place the piece of metal in a calorimeter filled with water. the piece of metal and water must be at different temperatures. Ideally, you would heat up the water and let it cool down. This change in temperature in the temperature that goes into the formula for the piece of metal. The only missing value is the heat which can be easily calculated because water' specific heat is known which can be used to calculate the heat loss by the water, which is the same as the heat gain by the piece of metal. With all the three values calculated and measured, you can simply plug them into the formula and solve for the specific heat of the metal.
Answer:
pH = 5.76
Explanation:
We can solve this problem by using<em> Henderson-Hasselbach's equation</em>:
pH = pKa + log
We are already know all the required information, thus we<u> input the data given by the problem</u>:
pH = 4.76 + log(20/2)
And finally <u>calculate the pH</u>:
pH = 5.76
The pH of that acetic acid solution is 5.76.