1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
myrzilka [38]
3 years ago
13

A student is using a coffee-cup calorimeter to determine the enthalpy change of the endothermic reaction of two aqueous solution

s. After both solutions are added to the cup, the student neglects to put the lid on the cup. This would cause the magnitude of the calculated ΔH° value to be: the answer is: too small, since the solution will absorb heat from the room. But why? Wouldn't depend on if the reaction releases or absorbs heat. Wouldn't it be too large because heat escapes the cup? I'm so confused
Chemistry
1 answer:
Liula [17]3 years ago
8 0

Answer:

See the answer below

Explanation:

<em>First, it should be understood that an endothermic reaction is one that absorbs energy in the form of heat from the surrounding.</em> The products of endothermic reactions usually have higher energy than their reactants. Hence, the ΔH° which is referred to as the enthalpy change is usually positive.

<u>Forgetting to cover the coffee-cup calorimeter means some of the heat energy absorbed by the reactants would be exchanged back to the surroundings - a loss.</u> It also means that the enthalpy change would be smaller compared to if the cup had been covered because some of the heat has been lost to the surrounding.

You might be interested in
How many electrons are transferred between the cation and anion to form the ionic bond in one formula unit of each compound? (1
rosijanka [135]
Here are the solutions:
For NaCl, there would be one electron transferred from the sodium atom, now producing a cation to the chlorine atom resulting in a chlorine anion. Forming ionic bond.
For CaS, there would be 2 electrons transferred from an atom of Ca to S, this can be obtained by simply looking at the ionic charges and or combining capacities of Ca.
For BaO, likewise, 2 electrons that are valence electrons are transferred from Ba to Oxygen.
In the ionic compound of KBr, the atom of K, potassium donated its one valence electron to Br, in need of it to achieve a stable octet, and produce the chemical bond.
Finally, LiF, a single valence electron is transferred from a metal atom of Li to F, for both of the atoms that would form the ionic bond to achieve a stable octet, and or full electron shell.
3 0
3 years ago
What is the volume of 120 x 1022 molecules of nitric oxide gas, NO, at si B) 2.24L C) 0.0199 L D) 5.02 A) 1120 L
Allisa [31]

Answer: 44.8 L

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 6.023\times 10^{23} of particles.

Standard condition of temperature (STP)  is 273 K and atmospheric pressure is 1 atm respectively.  

To calculate the moles, we use the equation:

\text{Number of moles}=\frac{\text{Given molecules}}{\text {Avogadro's number}}=\frac{120\times 10^{22}}{6.023\times 10^{23}}=2moles

1 mole of NO occupies volume = 22.4L at STP

Thus 2 moles of magnesium react with=\frac{22.4}{1}\times 2=44.8L

Thus the volume of 120\times 10^{22} molecules of nitric oxide gas is 44.8 L.

5 0
3 years ago
Which of the following statements is not correct?
Pavlova-9 [17]
Answer: This option is incorrect: <span>B. Covalent compounds are held together by much stronger interparticle forces than are ionic compounds.

Justification:

Ionic bonds, held by ionic compounds, are much stronger than covalent bonds, held by covalent compounds.

In ionic bonds one element yields one or more electrons forming a cation (a positively charged ion) and the other element accepts the electrons forming an anion (a negatively charged ion).

The anion and the cation are electrostatically atracted by each other. This electrostatic atraction force, named ionic bond, is very strong.

As result of this, the ionic compounds form strong crystals with high boiling and fusion points. A good example of this the sodium chloride, formed by the union of cation Na(+) and anion Cl(-).

The covalent bonds are result of sharing electrons and do not form ions. This bond is weaker than the ionic bond.
</span>
4 0
3 years ago
Which of the following is the energy of moving electrons?
mezya [45]

Answer:

Electrical energy

Explanation:

Electrical energy is caused by the moving of electrons.

hope it helps!

6 0
3 years ago
820 g Li2SO4 is dissolved into 2500 mL of solution. What is the molar concentration?
Andreas93 [3]

Molarity is defined as the moles of solute per liter of solution. M=\frac{n}{V}. Where M is molarity, n is the number of moles and V is the volume. First we must find the molar mass of Li_2SO_4 which is 109.98 g/mol

Li_2SO_4= 2 \times Li_{Ar} + S_{Ar} + 4 \times O_{Ar}\\= (2 \times 6.941 + 32.1 + 4 \times 16.0) = 109.98 g/mol

820\ g\ Li_2SO_4 \times \frac{mol}{109.98\ g}= 7.46\ mol\ Li_2SO4

Then we find the molarity using above equation

M= \frac{n}{V} = \frac{7.46 mol}{2500ml} \times\frac{1000ml}{L} = 2.98\ M


6 0
3 years ago
Other questions:
  • What type of bond forms in iron (2) bromine
    6·1 answer
  • Suppose you are asked to find the area of a rectangle that is 2.1-cm wide by 5.6-cm long. Your calculator answer would be 11.76
    8·1 answer
  • given the balanced equation representing a reaction 2NO+O2-&gt;2NO2+energy the mole ratio of NO to NO2 IS
    5·1 answer
  • What four elements did the ancient greeks think the world was made of ?
    6·2 answers
  • How many mL of a 5.0% glucose solution provide 80.0 g of glucose?
    12·1 answer
  • Fill in the coefficients that will balance the following reaction: __C3H8 + __O2 → ___CO2 + ___H2O
    5·1 answer
  • Trevor dissolves sodium hydroxide pellets in a beaker of water at room temperature, and notes that the beaker becomes warm. Whic
    9·2 answers
  • Which expression represents the pH of a solution?
    7·1 answer
  • How do prevailing winds affect air temperature?
    14·1 answer
  • Which statements correctly compare the masses of protons neutrons and electrons
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!