Answer:
D. 77.0%
Explanation:
% yield = actual yield/theoretical yield x 100%
% yield = 1.57 g / 2.04 g x 100%
% yield = 76.96 (round up)
Hi do you know this?
Answer:
2
Explanation
It seems logical
5) The stability of an atom is determined by
Re 1) P+n
2)P-n
3) P/N
4) N/P
Answer:
the answer p+n
Explanation:
The level of a liquid (i.e. distilled water) in laboratory glassware is determined by sight. The level corresponds to a specific volume. The volume is established by identifying the meniscus of the liquid relative to a calibration mark or series of calibration marks on the glassware (i.e. volumetric flask vs. buret). Which of the following statements is NOT correct when reading the meniscus?
a. the edge of the meniscus should be used to determine volume relative to the mark or marks
b. the meniscus should be read at eye level
c. when the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
d. the center of the meniscus should be used to determine volume relative to the mark or marks
Answer:
c. when the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
Explanation:
When we put a liquid in a pipette, we can see that the surface of that liquid will have a curve. This curve is called the meniscus and it has the correct volume that an aqueous solution has. However, for this, it is necessary that the meniscus is observed at eye level and that its edges and center are clearly visible.
Based on your answers to Question 3 above, why do you think that, as a general practice, when antibiotics
(including azithromycin) are prescribed to adults, the same dose is usually given, regardless of weight of the
patient?
Answer:
See explanation below
Explanation:
Since question 3 is not here, I will answer based on a general perspective.
The dosage of most antibiotics and drugs generally are prescribed without considering the weight of adults. Unlike children that are given dosages based on their weight.
The weight of adults is not considered because the extent to which they weigh is majorly as a result of their adipose (fat) tissue. And the adipose tissue does not determine the tolerance level of drugs. So an adult weighing 200kg and another weighing 50kg will be able to tolerate the same dosage of medications.
Because the adults are adults with fully developed organs, their weight does not matter when prescriptions are made.
Which of the following chemical reactions is a single displacement reaction?
A. 2Na + O2→
Na2O
B. 2A1 + 3Zn(NO3)2 2AI(NO3)3 + 3Zn
C. Pb(NO3)2 + 2KBr → PbBr2 + 2KNO3
D. 2Fe(OH)3 Fe2O3 + 3H2O
Answer:
B. 2A1 + 3Zn(NO3)2 --> 2AI(NO3)3 + 3Zn
Explanation:
In the chemical equation, you can see that 2Al replaced 3Zn with (NO3)3 in the product, thus it is a single displacement reaction.
Answer:
B. 2A1 + 3Zn(NO3)2 --> 2AI(NO3)3 + 3Zn
Explanation:
Calculate: Press Reset. Start with 1.900 × 10 24(or 19.00 × 10 23 ) molecules of Cu2O. A. Calculate the number of moles: B. Use the Gizmo to verify your calculation. Were you correct? C. Is the method for converting molecules to moles the same as that for atoms?
Answer:
1.661 mol.
Explanation:
Hello!
In this case, since the Avogadro's number allows us to relate the number of formula units in one mole of the substance; we need to keep in mind that elements are related by atoms and compounds by molecules, it means:
[tex]1 mol = 6.022x10^{23}atoms\\\\1 mol = 6.022x10^{23}molecules[/tex]
Thus, for copper (I) oxide, we compute the moles, given the atoms as shown below:
[tex]n = 1.900x10^{24}molecules*\frac{1mol}{ 6.022x10^{23}molecules} \\\\n = 1.661mol[/tex]
Thus, the method we use is the same.
Best regards
What is Kb for N2H4 if the pH of a 0.158M solution of N2H5Cl is 4.5?
Answer:
Kb[tex]= 1.58 * 10^{-6}[/tex]
Explanation:
The correct question is
What is Kb for N2H4 if the pH of a 0.158M solution of N2H5Cl is 4.5?
Solution-
N2H4Cl hydrolyses on addition of water
The reaction equation is as follows -
N2H4+ + H2O ----> N2H4 + H3O+
[tex]Ka = \frac{K_w}{K_b} = \frac{10^{-14}}{K_b}[/tex]
pH [tex]= 4.5[/tex]
[tex][H+] = 10^{-pH} = 10^{-4.5}[/tex]
[tex]K_b= \frac{10^{-14} }{K_b} = \frac{Y_2}{0.158} \\K_b= \frac{(10^{-4.5})^2}{0.158}\\=> Kb = 0.158 * 10-14 /(10-4.5)2[/tex]
Kb[tex]= 1.58 * 10^{-6}[/tex]
I’m thinking it’s the last one but I’m not sure.
Answer:
0.71 g/cm^3
Explanation:
Density = Mass ÷ Volume
So you would do 112.5 ÷ 159.3 which gives the result 0.71
I am running a reaction that creates 138 grams of sulfur trioxide (S03). My theoretical yield was 156 grams. What is my percentage yield?
Answer:
88.46%
Explanation:
Percentage yield is actual/theoretical * 100
138/156 * 100 = 88.4615385
Two colorless chemicals combine inside a glow
stick. When the chemicals combine, they produce
brightly colored light. The glow stick's temperature
does not change.
emission of heat
emission of light
color change
formation of gas
Answer:
Option B & Option C
Explanation:
correct on edge! :D
When chemicals combine chemical change takes place which is accompanied by emission of heat and light.
What is a chemical change?Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.
There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical changes:
1) inorganic changes
2)organic changes
3) biochemical changes
During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
Learn more about chemical change,here:
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Imagine a made-up pol
b. Write both the formula and the name for the compound formed when Cu2+
combines
with boritate? (2 pts)
Answer:
No change to the cation Add -ide to the anion
Question 1 and .2
Explanation:
GOOD REWARD
I will report those who gives random answers.
Answer:
3 mol AlCl₃.
Explanation:
Hello!
In this case, according to the specified reactants and products, it is possible to set up the following balanced chemical reaction:
[tex]Al(NO_3)_3+3NaCl\rightarrow 3NaNO_3+AlCl_3[/tex]
Whereas we evidence the 1:3 mole ratio between aluminum nitrate and sodium chloride; thus, since different moles were reacting, we need to identify the limiting reactant by computing the moles of AlCl₃ produced by each reactant as follows:
[tex]n_{AlCl_3}^{by\ Al(NO_3)_3}=4molAl(NO_3)_3*\frac{1molAlCl_3}{1molAl(NO_3)_3} =4molAlCl_3\\\\n_{AlCl_3}^{by\ NaCl}=9molNaCl*\frac{1molAlCl_3}{3molNaCl} =3molAlCl_3[/tex]
Thus, we infer that NaCl is the limiting reactant as it produces the fewest moles of AlCl₃; consequently the produced amount of this product is 3 mol.
Best regards!
can someone help me?
Answer:
no, and next time take it right
Explanation:
1. How many moles are in the following: a. 5 grams of Lici
Answer:
Number of moles = 0.1179 (Approx)
Explanation:
Given:
Mass of LiCl = 5 grams
Molar mass of LiCl = 42.39 g
Find:
Number of moles
Computation:
Number of moles = Mass / Molar mass
Number of moles = 5 / 42.39
Number of moles = 0.1179 (Approx)
What type of energy does a bouncing ball have ?
Answer:
Kinetic
Explanation:
When the ball is falling towards the table, it has kinetic energy. This elastic potential energy is why the ball is able to bounce, or rebound. After the ball rebounds, the elastic potential energy is transformed into kinetic energy, but it will never possess as much kinetic energy as during its original fall.
Answer:
Explanation:
It has kinetic energy.
Hope it helped you.
Italian dressing contains olive oil and vinegar, which will separate out from each other if left to sit. This makes the dressing a:
When an oxidant is present, vitamin C can be converted to a product described as (5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-furan-2,3,4(5H)-trione, which retains the furan-based nomenclature of vitamin C and describes the hydrogen placement at atom 5 of the ring. Which of the following statements best describes this vitamin C derivative?A) Vitamin C is reduced to yield a furan ring with 4 carbonyl groups and no double bonds.B) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and 1 double bond.C) Vitamin C is reduced to yield a furan ring with 1 carbonyl group and no double bonds.D) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and no double bonds
Answer:
D) Vitamin C is oxidized to yield a furan ring with 3 carbonyl groups and no double bonds
Explanation:
We can tell that the compound " (5R)-5-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-furan-2,3,4(5H)-trione " has 3 carbonyl groups due to it having "trione" in the name (and it lacking other carbonyl group names, like amide or carboxylic acid).
As there is no "-ene" part of the name referencing a double bond, the only option left is option D).
How many moles of KMnO4 are in 75g of KMNO4?
Answer:
0.64 mol
Explanation:
moles=mass/molar mass
n= 75/(39+14+4×16)
n=75/117
n = 0.64mol
Help, due tonight (2/19/2021) at 11:59pm!
Answer:
283549.68 J
Explanation:
From the question given above, the following data were obtained:
Mass (M) = 2.7 Kg
Initial Temperature (T₁) = 5.4 °C
Final temperature (T₂) = 30.5 °C
Specific heat capacity (C) = 4184 J/KgºC
Heat (Q) =?
The amount of heat energy needed can be obtained as follow:
Q = MC(T₂ – T₁)
Q = 2.7 × 4184 × (30.5 – 5.4)
Q = 11296.8 × 25.1
Q = 283549.68 J
Thus, the heat energy needed is 283549.68 J
Aqueous sulfuric acid H2SO4 will react with solid sodium hydroxide NaOH to produce aqueous sodium sulfate Na2SO4 and liquid water H2O. Suppose 59. g of sulfuric acid is mixed with 86.9 g of sodium hydroxide. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to 2 significant digits.
Answer:
22 g of water
Explanation:
The balanced chemical equation is:
H₂SO₄(aq) + 2 NaOH(aq) → Na₂SO₄(aq) +2 H₂O(l)
⇒ 1 mol of H₂SO₄ reacts with 2 moles of NaOH to produce 2 moles of H₂O.
First, we have to convert the moles to grams by using the molecular weight (Mw) of each compound:
Mw H₂SO₄ = (1 g/mol x 2 H) + 32 g/mol S + (16 g/mol x 4 O) = 98 g/molmass of H₂SO₄ = moles x Mw = 1 mol x 98 g/mol = 98 g
Mw NaOH = 23 g/mol Na + 16 g/mol O + (1 g/mol H) = 40 g/moLmass of NaOH = 2 moles x 40 g/mol = 80 g
Mw H₂O = (1 g/mol x 2 H) + 16 g/mol O = 18 g/moLmass of NaOH = 2 moles x 18 g/mol = 36 g
Now, we have to determine which is the limiting reactant. The stroichiometric ratio is 98 g H₂SO₄/80 g NaOH. We have 86.9 g of NaOH, so we need the following amount of H₂SO₄:
98 g H₂SO₄/80 g NaOH x 86.9 g NaOH = 106.4 g H₂SO₄
As we need more H₂SO₄ (106.4 g) than we have (59 g), the limiting reactant is H₂SO₄.
Finally, we calculate the mass of H₂O produced with the limiting reactant. The stoichiometric ratio is 36 g H₂O/98 g H₂SO₄, so we multiply the actual mass of H₂SO₄ by the stoichiometric ratio to calculate the maximum mass of H₂O produced:
mass of H₂O = 36 g H₂O/98 g H₂SO₄ x 59 g H₂SO₄ = 21.7 g ≅ 22 g
write the rate expression for the following reaction. H2+1/2
O2 arrow H2O
Answer:
[tex]r=-k[H_2][O_2]^{1/2}[/tex]
Explanation:
Hello!
In this case, according to the chemical reaction:
H2 + 1/2 O2 --> H2O
Since both hydrogen and oxygen are the reactants and the rate laws are written in terms of the concentration of reactants and the rate constant, we obtain:
[tex]r=-k[H_2][O_2]^{1/2}[/tex]
Whereas the negative sign represents the consumption of those reactants and the power 1/2 the stoichiometric coefficient of oxygen in the reaction.
Best regards!
The reaction Fe3O4 +C ---> CO2 + Fe can be balanced with the coefficients:
1,4,4,3
2.4.4.3
1,2,2,3
O 1,1,1,3
Answer:
the answer is 1,2,2,3
Explanation:
Fe3O4 +C ---> CO2 + Fe
1Fe3O4 +2C ---> 2CO2 + 3Fe
In a chemical reaction, reactants interact to form products. This process is summarized by a chemical equation. In the Balancing Chemical Equations Gizmo, look at the floating molecules below the initial reaction: H2 + O2 ???? H2O. 1. How many atoms are in a hydrogen molecule (H2)? 2. How many atoms are in an oxygen molecule (O2)? 3. How many hydrogen and oxygen atoms are in a water molecule (H2O)? 4. In general, what does a subscript (such as the "2" in H2) tell you about the molecule? 5. A chemical equation is balanced if the number of each type of atom on the left side is equal to the number of each type on the right side. Is this reaction balanced?
Answer:
See answer below
Explanation:
Let's write the equation again:
H₂ + O₂ ---------> H₂O
Now that we have written the equation, let's solve the exercise:
1. In this case, we first need to make a difference between atom and molecule. An atom is just a single element, a molecule it's when you have more than 1 element in a compound.
Knowing this, we have the H₂. In this case we only have one element, Hydrogen. However, as you can see in the expression, we have a number 2 as a subscript. The number 2 means that the hydrogen it's not alone, we do not have one hydrogen, we have two hydrogens, therefore, it becomes a molecule. Now, This molecule, according to the number 2 as subscript, means that the molecule of hydrogen have 2 atoms of hydrogens, and this formed the molecule, therefore, there are 2 atoms of hydrogens in H₂.
2. Following the same explanation of above, but using oxygen, we have the same thing, so, in a molecule of O₂, we have 2 atoms of oxygen.
3. The molecule of water is composed of Hydrogen and oxygen. As you can see, in this case we have 2 hydrogen and 1 oxygen, therefore, in 1 molecule of water, there are 1 atom of oxygen and 2 atoms of hydrogen.
4. The subscript, as you may know now, tell us the number of atoms that you have in a molecule or compound. This number also means, in different compounds the oxidation state of the atoms that conform the molecule.
5. No, the equation is not balanced, because we do not have the same number of oxygen on the side of the products. We need to balance that. As the oxygen is unbalanced, we just need to put numbers as coefficients, behind the molecule. This number will multiply the number of atoms of the referred molecule. So, doing this with the water on the products to equal the number of oxygen, we have:
H₂ + O₂ ---------> 2H₂O
But this 2, unbalance at the same time the number of hydrogens. We now have 4 hydrogens in the product, so, to balance this, we put a 2 on the reactants:
2H₂ + O₂ ---------> 2H₂O
Now the reaction is balanced.
Hope this helps
5. If you advance the movie one frame, the knot at point A would be
a) in the same place b) higher
c) lower d) to the right
e) to the left
relative to the hand
6. If you advance the movie one frame, the pattern of the waves will be
a) in the same place
b) shifted right
c) shifted left
shifted up
e)
shifted down
7.
If the person starts over and moves his hand more quickly, the peaks of the waves will be
a) the same distance apart
b) further apart
c) closer together
8. If you lower the frequency of a wave on a string you will
a) lower its speed. b) increase its wavelength. c). lower its amplitude. d) shorten its period
Answer:
5. higher
6. shifted down
7. closer together
8. increase its wave length
Explanation:
Which of the following would make a solution?
A. Oil in water
B. Sugar in water
C. Ice in water
D. Sand in water
SUBM
The combination from the available option that will make a solution would be sugar and water.
What are solutions?Solutions are obtained when solutes dissolve in solvents.
In other words, a solute must be able to dissolve in a solvent before a solution can be formed.
Oil and water cannot mix, and thus, cannot form a solution. Sand is insoluble in water and ice and water are the same.
Thus, the only option left is sugar and water. Sugar dissolves in water to form a sugar solution.
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The rate constant for a certain reaction is measured at two different temperatures:
temperature k
376.0 °C 4.8 x 10^8
280.0 °C 2.3 x 10^8
Assuming the rate constant obeys the Arrhenius equation, calculate the activation energy Ea for this reaction.
Answer: The activation energy Ea for this reaction is 22689.8 J/mol
Explanation:
According to Arrhenius equation with change in temperature, the formula is as follows.
[tex]ln \frac{k_{2}}{k_{1}} = \frac{-E_{a}}{R}[\frac{1}{T_{2}} - \frac{1}{T_{1}}][/tex]
[tex]k_1[/tex] = rate constant at temperature [tex]T_1[/tex] = [tex]2.3\times 10^8[/tex]
[tex]k_2[/tex] = rate constant at temperature [tex]T_2[/tex] = [tex]4.8\times 10^8[/tex]
[tex]E_a[/tex]= activation energy = ?
R= gas constant = 8.314 J/kmol
[tex]T_1[/tex] = temperature = [tex]280.0^0C=(273+280)=553K[/tex]
[tex]T_2[/tex] = temperature = [tex]376.0^0C=(273+376)=649K[/tex]
Putting in the values ::
[tex]ln \frac{4.8\times 10^8}{2.3\times 10^8} = \frac{-E_{a}}{8.314}[\frac{1}{649} - \frac{1}{553}][/tex]
[tex]E_a=22689.8J/mol[/tex]
The activation energy Ea for this reaction is 22689.8 J/mol
Consider the following reaction where K. = 9.52 10 2 at 350 K.
CH,(g) + CC14(2)—2CH2Cl2(g)
A reaction mixture was found to contain 2.21*10-2 moles of CH4(E), 3.8710-2 moles of CC1,(g) and 1.06-10-2 moles of CH,C12(2), in
a 1.00 liter container
Is the reaction at equilibrium?
If not, what direction must it run in order to reach equilibrium?
The reaction quotient, Qc equals
The reaction
A. must run in the forward direction to reach equilibrium
B. must run in the reverse direction to reach equilibrium
C. is at equilibrium
Answer:
The correct answer is A :))
Organic Molecules worksheet
Answer:
ok
Explanation:
If a machine has an AMA of 1 what does this tell you about the RF and EF?
Answer:
Although you might think of a machine as complex system of gears, drive belts and and a motor, the definition physicists use is much simpler. A machine is simply a device that does work, and there are only six different types of simple machines. They include the lever, the pulley, the wheel and axle, the screw, the wedge and the inclined plane.
Explanation:
Calculate the molar it’s of a solution containing 29g of glucose dissolved in 24.0 g of water