Lab: Enthalpy.
What were the learning goals of this lab experiment? Check all that apply.
to use mass and temperature data to do computations involving heat
to demonstrate that different reactions have different enthalpies
to compute a reaction’s enthalpy directly using mass measurements and a calorimeter
to compute the enthalpy of a reaction that cannot be measured directly using a simple calorimeter
Hess
’s law allows you to find the net enthalpy of the magnesium combustion by adding the enthalpies of intermediate reactions.
To find the enthalpy of a reaction in the lab, you measured the
mass
of the reactants
and the
temperature
change during the reaction.
In both Reactions 1 and 2, the temperature change was
positive
, meaning that the
reactions
gave off
heat.

Answer:

11.1249387366083

Explanation:

you do -log([H+]

Answer:

1.332 L

Explanation:

The reaction that takes place is:

First we calculate the number of NaOH moles, using the given volume and concentration:

Then we convert NaOH moles into H₂SO₄ moles, using the stoichiometric coefficients:

Finally we calculate the required volume of a 1.75 M solution of H₂SO₄, using the concentration and number of moles:

We can convert mL into L:

Answer:

0.3832

Explanation:

Givens

m = 437.2 grams

c = ?

delta t = 69.8 - 19.3

H = 8460 J

Formula

H = m*c*Δt

Solution

8460 = 437.2 * c * (69.8 - 19.3)

8460 = 437.2 * c * 50.5

8460 = 22078.6 * c

c = 8460 / 22078,6

c = .3832 J / (oC * gr)

Answer:

As of right now (4-7-2021), the physical science requirement for the SLP certificate must be met by completing coursework in the areas of either chemistry or physics.

Answer:

3.7 x 10²¹ O₂ molecules

Explanation:

2KClO₃ => 2KCl + 3O₂

given 0.500g KClO₃ => 0.500g/122.55g/mol = 0.0041 mole KClO₃

0.0041 mole KClO₃ => 3/2(0.0041) mole O₂ = 0.0061 mole O₂

0.0061 mole O₂ = 0.0061 mole O₂ x 6.02 x 10²³ molecules O₂/mole O₂

= 3.7 x 10²¹ molecules O₂

Answer:

A

Explanation:

The weak base ionization constant (Kb) for [tex]C_{4} H_{4} N_{2}[/tex] is equal to Option A.

A weak foundation is a base that makes ionize only slightly in an aqueous solution. Remember that a foundation can be defined as an object, which receives a hydrogen ion from another object.

To obtain an aqueous solution of a weak acid, the dissociation constant is called the acid ionization constant (Ka). Similarly, the constant equilibrium of a weak base reaction with water is the base ionization constant (Kb). In any conjugate acid-base pair, KaKb = Kw.

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Answer:

35.8g of Cl₂ is the yield

Explanation:

Based on the reaction:

MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂

1 mole of MnO₂ and 4 moles of HCl react producing 1 mole of Cl₂

To solve this question we must find limiting reactant. with limiting reactant we can find the theoretical yield of Cl₂. As the actual yield is the 62.7% we can find actual yield of Cl₂ in grams:

Moles MnO₂ -Molar mass: 86.9368g/mol-:

70.0g * (1mol / 86.9368g) = 0.805 moles

Moles HCl -Molar mass: 36.46g/mol-:

128.0g * (1mol / 36.46g) = 3.51 moles

For a complete reaction of 3.51 moles of HCl are required:

3.51 moles HCl * (1mol MnO₂ / 4mol HCl) = 0.878 moles MnO₂.

As there are just 0.805 moles of MnO₂, MnO₂ is limiting reactant.

1 mole of MnO₂ produce 1 mole of Cl₂. The theoretical moles of Cl₂ produced are 0.805 moles.

As the yield is of 62.7%, the yield of Cl₂ is:

0.805 moles * (62.7 / 100) = 0.505 moles Cl₂. In grams:

0.505 moles Cl₂ * (70.906g / mol) =

Answer:

Avogadro's constant says that  

1

mole of any atom contains  

6.022

⋅

10

23

atoms. In this case you have  

3.40

⋅

10

22

atoms:

3.40

⋅

10

22

atoms

6.022

⋅

10

23

atoms

mol

=  

5.65

⋅

10

−

2

m

o

l

Step 2

The atomic mass of helium (He) will give you the weight of one mole of this molecule:  

1

mol =  

4.00

gram:

4.00

g

mol

⋅

5.65

⋅

10

−

2

mol

=  

0.226

g

So the  

3.40

⋅

10

22

helium atoms weigh  

0.226

gram

.

Explanation:

Mark as brainlyiest

HCH bond angle is ~110 degrees.

Answer:

Hello your question is incomplete attached below is the complete question

answer : 6,7-dimethyl-3-nonanone ( B )

Explanation:

The product for the following reaction sequence as attached below is

6,7-dimethyl-3-nonanone

The following reaction sequence can be categorized under Carbon Nucleophiles.

Carbon Nucleophiles which can be used to convert  aldehydes and ketones into  carboxylic acids or alkenes.

The product for the given reaction sequence is 6,7-dimethyl-3-nonanone.

IUPAC (International Union of Pure and Applied Chemistry) naming is a systematic method used to name chemical compounds according to a set of rules established by the IUPAC.

The purpose of IUPAC naming is to provide a consistent and unambiguous way to communicate the structure of a compound through its name.

The outcome of the subsequent chain of reactions, which is appended below, is 6,7-dimethyl-3-nonanone

Under the heading of Carbon Nucleophiles, the following reaction chain can be categorised.

Aldehydes and ketones can be transformed into carboxylic acids or alkenes using carbon nucleophiles.

Thus, the answer is 6,7-dimethyl-3-nonanone.

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Your question seems incomplete, the probable complete question is:

Answer:

+.0.94%

Explanation:

Relative and average atomic mass both describe properties of an element related to its different isotopes. Out of these two Relative atomic mas is more accurate. Thus the % relative error in his weight measurements is +.0.94%.

Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes. It can be calculated by multiplying mass of a isotope to natural abundance of that isotope.

The relative mass is the mass that is with respect to mass of a matter that is considered as standard. In chemistry relative mass is equal to the mass of one-twelfth the mass of C-12 isotope .

% relative error=(Difference in weight÷ original weight)×100

Difference in weight= original weight -calculated weight

original weight=1.0755 g

calculated weight=1.0555 g

Difference in weight= 1.0755 g-1.0555 g=0.02g

% relative error=(0.02g÷ 1.0755 g)×100

                         =+.0.94%

Thus the % relative error in his weight measurements is +.0.94%.

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Answer:

I'm very sure it's thermal energy.

Explanation:

Answer:

thermal energy is the answer

Answer:

Ternary

Explanation:

A ternary ionic compound is an ionic compound composed of three or more elements. Copper II Nitrate is a ionic compound and contains 3 elements thus making it Ternary

Answer:

C

Explanation:

because then you'd be able to make a group to raid, run with you, and save more people.

Explanation:

by dissolving the mixture of lead sulphate and lead chloride in water we can separate the two. after dissolving the mixture on water lead sulphate can be obtained as the solid that 's left behind lead chloride can be recovered by evaporating.

Answer:

Cu⁺² is being reduced in that reaction.

Explanation:

When a substance is reduced, its oxidation number is reduced -changing to a lower value than original-.

Cu⁺² turned into Cu. Meaning that the oxidation number changed from +2 to 0.

Thus, Cu⁺² is being reduced in that reaction.

Answer:

The incorrect or the false options are -

(B) - If NH4NO3 is added, the pH becomes more basic.

(D) - If a small amount of HCl is added, the pH becomes slightly more basic.

 (E) - If NaOH is added, the OH- ions react with the [tex]NH_3[/tex].

Explanation:

The given solution the buffer basic .

Therefore , the options A ( If a small amount of NaOH is added, the pH becomes slightly more basic.) and C ( If HCl is added, the H+ ions react with the NH3.) All other B , D , E are false .

Answer:

True

Explanation:

I learned about it a few years ago

Answer:

See explanation

Explanation:

The acetoxy group in ortho position in phenyl acetate does interact with the phenyl moiety in the molecule via resonance.

This detailed interaction of the  acetoxy group in ortho position in phenyl acetate with the phenyl moiety in the molecule via resonance is shown in the image attached.

This interaction is made possible because the oxygen atom of the acetoxy group has lone pairs of electrons that are suitably positioned to interact with the ring via resonance.

Answer:

E  3.0 x 10² mL.

Explanation:

Hello there!

In this case, according to the formula for the calculation of the mass-volume percent:

[tex]\% m/V=\frac{m_{solute}}{V_{solution}}*100\%[/tex]

Whereas it is necessary to know the mass of the solute and the volume of the solution. Thus, given the mass of NaOH as the solute, the volume of the solution would be:

[tex]V_{solution}=\frac{m_{solute}}{\% m/V}*100\%[/tex]

Then, by plugging in we obtain:

[tex]V_{solution}=\frac{75g}{25\%}*100\%\\\\V_{solution}=3.0x10^2mL[/tex]

Thus, the answer is E  3.0 x 10² mL.

Best regards!

Answer:

The human brain is the body's control center, receiving and sending signals to other organs through the nervous system and through secreted hormones. It is responsible for our thoughts, feelings, memory storage and general perception of the world. The human heart is a responsible for pumping blood throughout our body

According to my notes, nucleophilicity order is directly proportional to basicity order in an aprotic medium, and is inversely proportional to basicity order in protic medium. And H2O is a stronger base than H2S, so it should be the strong nucleophile, but the answer is given as H2S is the stronger nucleophile.

hope this helped, good luck <3

Answer:

When science educators teach nurses, their primary aim should be to help them to develop understanding of their world of nursing. From a study of registered nurses' conceptions of the physical science underlying their clinical practice, we assert that nurses' understanding of the physical sciences is inadequate in terms of the competencies required of them as nurses.

Explanation: Hopes this helps You A lot :-D

Answer:

8Al+3Fe3O4=4Al2O3+9Fe

Answer:

8Al + 3Fe3O4 → 4Al2O3 + 9Fe

Explanation: