Answer:
The first one is ground and the second one is excited
Explanation:
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.
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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
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
Consider the following elementary reaction:
2NO(g) → N2O2(g)
Suppose we let k1 stand for the rate constant for this reaction, and k-1 stand for the rate constant of the reverse reaction. Write the expression that gives the equilibrium concentration of NO in terms of k1, k-1. And the equilibrium concentration of N2O2.
Answer:
[tex][NO]=\frac{k_{-1}}{k_1} [N_2O_2][/tex]
Explanation:
Hello!
In this case, since the reaction may be assumed in chemical equilibrium, we can write up the rate law as shown below:
[tex]r=-k_1[NO]+k_{-1}[N_2O_2][/tex]
However, since the rate of reaction at equilibrium is zero, due to the fact that the concentrations remains the same, we can write:
[tex]0=-k_1[NO]+k_{-1}[N_2O_2][/tex]
Which can be also written as:
[tex]k_1[NO]=k_{-1}[N_2O_2][/tex]
Then, we solve for the concentration of NO to obtain:
[tex][NO]=\frac{k_{-1}}{k_1} [N_2O_2][/tex]
Best regards!
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: 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
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
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.
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
Number of liters in 0.50 moles of O2
Answer:
there are about 11.2 liters
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]
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!
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 :))
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).
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 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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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
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)
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 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 the molar it’s of a solution containing 29g of glucose dissolved in 24.0 g of water
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:
Hi do you know this?
Answer:
2
Explanation
It seems logical
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!
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.
Organic Molecules worksheet
Answer:
ok
Explanation:
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
Italian dressing contains olive oil and vinegar, which will separate out from each other if left to sit. This makes the dressing a:
What does an ion have that an atom does not?
Answer:
Atoms are neutral; they contain the same number of protons as electrons. By definition, an ion is an electrically charged particle produced by either removing electrons from a neutral atom to give a positive ion or adding electrons to a neutral atom to give a negative ion.
Explanation:
:)
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: