We know the moles of solute: 0.875 moles of glucose. We can easily determine the liters of solution by using the mass of water given (1.5 kg) and the density of water (approximately 1 kg/L): they're, for all intents and purposes, equal (the approximation isn't large enough to be appreciable here, nor would the volume of the solution appreciably change since the solute is a solid that will <em>dissolve into </em>the solvent). So, we have 1.5 L of solution.
Now, we plug in what we have:
molarity = 0.875 moles of glucose/1.5 L of solution = 0.58 M glucose
The answer is provided to two significant figures since we're given the mass of water to two significant figures.
An endothermic reaction is a type of reaction that absorb energy from the environment, thus, the energy level of the product is always higher than that of the reactants. During endothermic phase change, the potential energy of the system always increases while the kinetic energy of the system remains constant. The potential energy of the reaction increases because energy is been added to the system from the external environment.
Taking into account the definition of calorimetry, 0.0185 moles of water are required.
<h3>Calorimetry</h3>
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).
So, the equation that allows to calculate heat exchanges is:
Q = c× m× ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
<h3>Mass of water required</h3>
In this case, you know:
Heat= 92.048 kJ
Mass of water = ?
Initial temperature of water= 34 ºC
Final temperature of water= 100 ºC
Specific heat of water = 4.186
Replacing in the expression to calculate heat exchanges:
92.048 kJ = 4.186 × m× (100 °C -34 °C)
92.048 kJ = 4.186 × m× 66 °C
m= 92.048 kJ ÷ (4.186 × 66 °C)
<u><em>m= 0.333 grams</em></u>
<h3>Moles of water required</h3>
Being the molar mass of water 18 , that is, the amount of mass that a substance contains in one mole, the moles of water required can be calculated as: