Select the atom that will attract the electron pair (:) more strongly (the atom with the greater electronegativity)

In the Energy and Specific Heat lab, what temperature should be recorded as the final temperature of the water when measuring th

Anon25 [30]

Answer:

B. The temperature of the water when the food sample has finished burning completely.

Explanation:

Heat or thermal energy is a form of energy that transfers from one object to another due to a temperature difference between the objects. The units for heat are joules or calories.

Calorimetry is the measurement of heat energy released or absorbed in a chemical reaction. A calorimeter is used in calorimetry. The calorimeter operates on the Law of Conservation of Energy which states that energy is never created or destroyed but is transformed from one form to another or between objects.

In food calorimetry, the energy released when food is burned is measured by recording the rise in temperature of water in a calorimeter when a given mass of a food sample is burned completely.

Energy can be calculated using the formula: Q = mc ∆T

where Q = the energy in joules or calories, m = the mass in grams, c = specific heat and ∆T = the change in temperature (final temperature - initial temperature).

The temperature of the water when the food sample has finished burning completely is taken as the final temperature of the water. The sample is allowed to smolder for sometime before recording the final water temperature. This is because the water temperature will continue to rise after the flame has gone out.

6 0

3 years ago

The C2-C3 single bond in butane freely rotates at room temperature, see equation (1) below. In contrast, the C2-C3 single bond i

Murrr4er [49]

Answer: Rotation occurs at single bonds that are sigma bonds. Rotational barrier is the amount of activation energy required to covert rotamer to another by rotation that occurs around the sigma bond(C-C single bond). Due to the presence of steric hindrance that is the nonbonding interaction effects the reactivity of ions and molecules, activation energy increases. So the rotational barrier in butenyl cation is high.

8 0

3 years ago

When 2.3 × 10^3 g of CaCO3 are heated, the actual yield of CaO is 1.09 × 10^3g. What is

iren [92.7K]

The percent yield : 4. 84.58%

<h3>Further explanation</h3>

Reaction

CaCO₃ ⇄ CaO+CO₂

mass CaCO₃ = 2.3 × 10³ g

mol CaCO₃ (MW=100.0869 g/mol) :

$\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{2.3\times 10^3}{100,0869}\\\\mol=22.98$

From the equation, mol CaCO₃ : CaO = 1 : 1, so mol CaO=22.98

mass CaO(MW=56.0774 g/mol)⇒ (theoretical) :

$\tt mass=mol\times MW\\\\mass=22.98\times 56,0774\\\\mass=1288.659~g$

The percent yield :

$\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\\%yield=\dfrac{1090}{1288.659}\times 100\%\\\\\5yield=84.58\%$

5 0

3 years ago

HCl(aq) + KOH(aq) → H 2O(ℓ) + KCl(aq)

fredd [130]

Answer:

try a science calculator

Explanation:

5 0

2 years ago

For many purposes we can treat ammonia (NH) as an ideal gas at temperatures above its boiling point of -33.C. Suppose the temper

levacccp [35]

Answer:

In homeothermic (“warm-blooded”) animals, body temperature is carefully

regulated. The hypothalamus, located in the brain, acts as the master ther-

mostat to keep body temperature constant to within a fraction of a degree

Celsius in a healthy animal. If the body temperature starts to deviate much

from the desired constant level, the hypothalamus causes changes in blood

flow and initiates other processes, such as shivering or perspiration, to bring

the temperature back to normal. What evolutionary advantage does a con-

stant body temperature give the homeotherms (e.g., birds and mammals)

over the poikilotherms (e.g., reptiles and insects), whose body temperatures

are not kept constant? What are the disadvantages?

Explanation: Basic chemical understanding as revealed upwards

6 0

3 years ago