The question incomplete , the complete question is:
A student dissolves of 18.0 g urea in 200.0 mL of a solvent with a density of 0.95 g/mL . The student notices that the volume of the solvent does not change when the urea dissolves in it. Calculate the molarity and molality of the student's solution. Round both of your answers to significant digits.
Answer:
The molarity and molality of the student's solution is 1.50 Molar and 1.58 molal.
Explanation:
Moles of urea = 
Volume of the solution = 200.0 mL = 0.2 L (1 mL = 0.001 L)

Molarity of the urea solution ;

Mass of solvent = m
Volume of solvent = V = 200.0 mL
Density of the urea = d = 0.95 g/mL


(1 g = 0.001 kg)
Molality of the urea solution ;


The molarity and molality of the student's solution is 1.50 Molar and 1.58 molal.
33233728793278237876548742787874578378572098-2932-=93788784787489
2.23 moles of propane react when 294 g of CO₂ is formed .
<h3>What is moles ?</h3>
Moles is a unit which is equal to the molar mass of an element.
A reaction is given
C₃H₈ +50₂ → 3CO₂ + 4H₂O
Grams of CO₂ formed = 294 gm
In moles = 294 /44 = 6.68 moles.
Let x be the moles of C₃H₈ is x
Mole ratio of CO₂ to C₃H₈ = 3 : 1
so
6.68 /x = 3/1
x = 6.68 /3 = 2.23 moles
Therefore 2.23 moles of propane react when 294 g of CO₂ is formed .
To know more about Moles
brainly.com/question/26416088
#SPJ1
The structure of the alkyl bromides used in a malonic ester synthesis of ethyl 2-methyl-4-pentenoate.
Ethyl 2-methyl-4-pentenoate by Malonic ester synthesis.
The alkylation of diethyl malonate or a related ester of malonic acid at the carbon alpha (immediately next) to both carbonyl groups, followed by conversion to a substituted acetic acid, characterizes the chemical reaction known as the malonic ester synthesis.
As a result, it is evident from the structure of ethyl 2-methyl-4-pentenoate that ethyl and methyl bromides are the alkyl bromides employed.
To learn more about Malonic ester synthesis refer here:
brainly.com/question/17237043
#SPJ4
Answer:
Yes, wind and temperature are responsible for the spreading of fire.
Explanation:
Chemistry play a key role in the chemical reaction that is occurring in the wildfires because chemistry is the study of chemicals and in wildfires, the reaction of chemicals is responsible for the occurring and spreading of fire. Yes, wind currents and temperature has a great influence on the fire spreading in the forests. The fire occurs in the forest is due to temperature while its spreading happens due to wind. Placing water on the fire does not help extinguish the fire because the the fire particles can be transmitted for a fair distance by wind.