Which of the following are acid formulas? (Choose 2)
NH3
CH3OH
NaOH
HNO3
H2SO4
CH4
Answer:
HNO3 & H2SO4
Explanation:
HNO3 is Nitric acid and H2SO4 is Sulphuric acid
Alkenes are more stable than alkanes. True or False
Answer:
Yes
Explanation:
Alkenes are relatively stable compounds, but are more reactive than alkanes because of the reactivity of the carbon–carbon π-bond. Most reactions of alkenes involve additions to this π bond, forming new single bonds.
True or False
a. The cones in our eyes detect color, while the rods perceive brightness.
b. In white light, white objects absorb all the colors.
c. At night, when light is dim, our cones are not activated so objects will appear as their normal color.
P.
d. Violet has the longest wavelength which is why it gets refracted the most.
V
e. The angle of incidence always equals the angle of reflection.
true
false
true
true
false
PLEASE HELP!
The specific heat of octane, C8H18(l), is 2.22 J/(g⋅K).
How much heat is needed to raise the temperature of 76.0 g of octane from 10.6 ∘C to 26.0 ∘C?
Express your answer in joules to three significant figures.
Answer:
Q = 2.60 • [tex]10^{3}[/tex] J
Explanation:
Our specific heat capacity equation is:
Q = mC∆T
Q is the energy in joules.
m is the mass of the substance.
∆T is the temperature chance.
Let's plug in what we know.
We have 76.0 g of octaneThe specific heat capacity of octane is 2.22 J/(g•K)The temperature increases from 10.6º to 26.0º (a 15.4º increase)Q = 76.0(2.22)(15.4)
Multiply.
Q = 2598.288
We want three significant figures.
Q = 2.60 • [tex]10^{3}[/tex]
or
Q = 2590 J
Hope this helps!
Answer:6,985.008
Explanation:
so the hear formula is mass times specific heat times change in temperature (kelvin) so what i did was got the change in temperature (41.4 K) and multiplied that times 2.22 J/(g•K)and multiplied that by 76 grams of Octane to get the Answer (not in scientific notation)
Choose the options below that are true of standard reduction potential. (select all that apply) Select all that apply: All standard reduction potentials are measured against that of the reduction of hydrogen ions to H2 gas. The standard reduction potential of a cell is determined by subtracting the standard reduction for the reaction at the anode from the standard reduction potential for the reaction at the cathode. Standard reduction potentials are dependent on reaction stoichiometry. The standard reduction potential for a cell is determined by adding the standard reduction potential for the reaction at the anode to the standard reduction potential for the reaction at the cathode.
Answer:
All standard reduction potentials are measured against that of the reduction of hydrogen ions to H2 gas.
Explanation:
The standard hydrogen electrode (SHE) serves as a sort of reference electrode. All standard electrode potentials of chemical systems are measured against the standard hydrogen electrode whose electrode potential has been arbitrarily set at 0.00 V.
The reduction potential of any other system is measured against the standard hydrogen electrode by connecting that half cell to the standard hydrogen electrode and observing the reading of the voltmeter. The standard hydrogen electrode consists of hydrogen ions of unit activity, hydrogen gas at 1 atm and the system is maintained at a temperature of 298 K.
Standard reduction potentials are measured against that of the reduction of hydrogen ions to [tex]H_2[/tex] gas because hydrogen is chosen as a standard reference and has electrode potential zero.
It is impossible to measure absolute electrode potential for an electrode without forming cell . Therefore it is assumed that standard electrode potential for hydrogen is zero
The standard reduction potential of a cell is determined by subtracting the standard reduction for the reaction at the anode from the standard reduction potential for the reaction at the cathode.
[tex]E_c_e_l_l[/tex]°[tex]= E_c_a_t_h_o_d_e[/tex]°[tex]- E_a_n_o_d_e[/tex]°
The species liking to get reduced is defined in term of standard reduction potential.
The species whose standard reduction potential is to be calculated is placed at cathode and at anode hydrogen electrode is used.
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PLEASE QUICKLY. I'll give BRAINLIEST. A sample contains 25% parent isotope and 75% daughter isotopes. If the half-life of the parent isotope is 72 years, how old is the sample?
144 years old
216 years old
288 years old
360 years old
From the calculations and the principles of radioactivity, the age of the parent isotope is 144 years
What is radioactivity?The term radioactivity has to do with the spontaneous decay of a substance.
We know that we have about 25% parent isotope still remaining hence;
[tex]0.693/t1/2 =2.303/t log No/N\\When N =0.25 No and t1/2 = 72 years\\0.693/72 =2.303/t log No/0.25No\\0.0096 = 2.303/t *0.60206\\0.0096 = 1.3865/t\\t = 1.3865/0.0096\\t =144 years[/tex]
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Answer:
A. 144 years old
Explanation:
Teresa has taken three tests worth 100 points each. Her scores are 85, 93, and 88. She has one test left to take.
To get an average score of 90, what must the sum of all her test scores be?
a.
400
c.
600
b.
360
d.
300
Answer:
SOrry it makes me writer sotufjksankdn
Explanation:
how many grams of caco3 are needed to react with 15.2g of hcl
Answer:
Balanced equation:
CaCO3 (s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
1mol CaCO3 will react with 2 mol HCl
Mol HCl in 32.8mL of 1.25M solution = 32.8mL / 1000mL/L * 1.25mol /L = 0.041 mol HCl
This will react with 0.041/2 = 0.0205 mol CaCO3
Molar mass CaCO3 = 100g/mol
Mass of CaCO3 reacted = 0.0205mol *100g/mol = 2.05g CaCO3.
Grams are the unit of weight or mass that depicts the quantity of a substance. The mass of calcium carbonate reacted is 2.05 gm.
What is mass?Mass is the product of the moles of the compound and its molar mass, it is given in grams.
The balanced chemical reaction is given as:
[tex]\rm CaCO_{3} (s) + 2HCl(aq) \rightarrow CaCl_{2}(aq) + CO_{2}(g) + H_{2}O(l)[/tex]
From the reaction, 1 mole of calcium carbonate reacts with 2 moles of hydrochloric acid.
Moles of hydrochloric acid is calculated as:
[tex]\begin{aligned} \rm n &= \rm Molarity \times Volume (L)\\\\&= 0.0328 \times 1.25\\\\&= 0.041\;\rm mol\end{aligned}[/tex]
Now, the moles of calcium carbonate it will react with will be 0.0205 moles.
Mass of calcium carbonate is calculated as:
[tex]\begin{aligned} \rm mass &= \rm molar\; mass \times moles\\\\&= 0.0205 \times 100\\\\&= 2.05 \; \rm g\end{aligned}[/tex]
Therefore, 2.05 gm of calcium carbonate is needed to react with 15.2 gm of hydrochloric acid.
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Can someone please help, 20 points
Draw 3-ethyl-2,4-dimethyl octanoic acid
3-ethyl-2.4-dimethyl-octanoic acid
A gas has an initial pressure of 120 kPa, a volume of 23 liters, and a temperature of 20°C. If the pressure is raised to 150 kPa the new volume is 17 liters, what is the new temperature of the gas? *
A.100 K
B.0.003 K
C.270.7 K
D.18.4 K
HELP!! Suppose that the pressure of 1.00 L of gas is 380 mm Hg when the temperature is 200. K. At what
temperature is the volume 2.00 L and the pressure 0.750 atm?
What is the pH of a solution with an H3O+ concentration of 5.67 x 10-4 M?
a. 1.00
b. 3.25
C. -1.00
d. -3.25
Answer:
3.25Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ { H_3O}^{+}][/tex]
From the question we have
[tex]ph = - log(5.67 \times {10}^{ - 4} ) \\ = 3.2464[/tex]
We have the final answer as
3.25Hope this helps you
I’d appreciate the help! :)
Here is the reaction:
3 NO2 (g) + H2O (l) = 2HNO3 (l) + NO (g)
Answer: 300g
Explanation:
first we write the given values on top
224L. x
3 NO2 (g) + H2O (l) = 2HNO3 (l) + NO (g)
22.4L 30g
then we form a formula
224L/22.4L= x/30g
224*30/22.4
6720/22.4= 300g
El petróleo crudo, es decir, en estado natural,
se encuentra embebido en las rocas porosas de
la corteza terrestre, semejante al agua en una
esponja, y no a manera de lagos subterráneos,
como se cree. Por lo general, el pozo petrolero
contiene en su parte superior una gran masa de
gas. Responde:
a) ¿Qué precauciones se deben tener en la explo-
tación del petróleo?
b) ¿Cuál es el impacto ambiental de la explotación
del petróleo?
c) ¿Qué compromisos debe cumplir una em-
presa que explota el petróleo en relación con el
medio ambiente?
Balance the following equation:
Cr + __02 +_Cr203
Answer:
4Cr + __302 -->_2Cr203.....
Use the equation below:
2Na + Cl2 ==> 2NaCl
+ O
How many grams of NaCl are produced when 1.25 moles of Cl2 reacts with Na?
Explanation:
2/1×1.25
=2.5 mole of NaCl are produced
weight of NaCl produced = moles × molar mass of NaCl
weight of NaCl produced = 2.5×58.5
weight of NaCl produced =146.5 grams
How many moles of aluminum sulfide will be produced if 12 moles of Sg react?
Answer:
Molar mass = [9(12.0)+8(1.01)+4(16.0)] = 180.1 g/mol Moles = 112 g 1 mol x 180.1 g = 0.622 mol (3 sig figs)
Explanation:
please answer cansend to me
What is the main purpose of phloem tissue?
to carry food from the leaves to all the cells of the plant
to absorb water and minerals from the soil
to store extra food for the plant to use in the winter
to carry water and minerals from the roots to the lea
why metal in the middle of metal activity series can't be obtained by heating ors in air
Answer:
See Explanation
Explanation:
The way by which a metal is obtained from its ore is determined by the chemical reactivity of the metal.
Metals that are highly reactive are chiefly obtained by electrolysis of the metal salt. These metals are found high up in the metal activity series.
Metals that are at the middle of the series are moderately reactive and are obtained by electrolysis or by reduction since they still form ionic salts.
Metals that are far lower in the series can only be obtained by heating them in air because they are mostly unreactive.
Hence, moderately reactive metals at the middle of the series are not obtained by roasting in air.
Carbon dioxide and water are produced when pentane (C5H12) reacts with oxygen. What is the balanced equation for this reaction?
○C5H12(g) + O29) - CO2(g) + H2O(g) ○C5H12(g) + O2(g) - 5CO2(g) + H2O(g)
○C5H12(g) +802(g) - 5CO2(g) + 6H2O(g) ○5CO2(g) + 6H2009) - C5H12(g) + 802(g)
○C5H12(g) +502(g) - 5CO2(g) + 6H2(g)
○CH2(g) +O2(g) + CO2(g) + H2(g)
Answer:
C
Explanation:
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g)
The balanced chemical equation of pentane (C5H12) which reacts with oxygen is
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g)
What is balanced chemical equation?It is the chemical equation in which the atom or molecules or moles of elements on both side reactant and product.
Our reactants are pentane and oxygen. Since, fourth and sixth reaction do not contain pentane. Therefore, fourth and sixth reaction are wrong.
Now, our next step is to compare product.
As we know that, Carbon dioxide and water are produced when pentane (C5H12) reacts with oxygen. So, we get to the conclusion that carbon dioxide and water are the product.
Since, rest of the equation have carbon dioxide and water as product.
On reactant side, there are 5 carbon atoms and 12 hydrogen atom. So, on product side there must be 5 carbon atoms and 12 hydrogen atom. Now we balance the oxygen atom on both side.
Thus, we concluded that the balanced chemical equation of pentane (C5H12) which reacts with oxygen is
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g).
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Gas particles that are at low temperature and high pressure and are close to changing phases are considered:
a)Real Gases
b)Ideal Gases
c)Both Ideal and Real Gases
Please choose a claim and then answer the question below please ty I would appreciate it!
Answer:
Claim 1
Explanation:
I chose this claim because I believe that when the plates under the earth move or shift, that's what causes an earthquake and when everything starts to shake. If it was the other way around there wouldn't be any reason for an earthquake to start.
hope that helped :)
Answer:
Plates move, which can cause earthquakes.
Explanation:
Tectonic plates are always slowly moving, however sometimes they can "lock" together, creating pressure and build up. The release of this energy results in a Tectonic earthquake. Therefore, the movement of plates causes earthquakes.
The back of a water droplet acts as a mirror. When light hits the back of the water droplet, it bounces back to our eyes. This is called ____________.
Water can keep engines operating at low temperatures. Which property of water most likely gives it this ability?
A. it boils at around 100°C
B. it has a high heat capacity
C. it is a good lubricant
D. it can change from water to ice
Answer:
B: it has a high heat capacity
Explanation:
When any material has a high specific heat capacity/ heat capacity, it doesn't heat or cool very fast. So water can absorb more heat from the engine and can keep the engine cool or at low temperature for a longer period of time.
How many formula units are there in 14.50 moles of any compound?
___X 10^___formula units
Answer:
8.73 × 10²⁴ formula units
Explanation:
To calculate the number of formula units a substance contain, we multiply the number of moles by Avagadro number (6.02 × 10²³)
number of formula units = 14.50 moles × 6.02 × 10²³
= 87.29 × 10²³
= 8.73 × 10²⁴ formula units.
What is the mass of a sample of NH3 containing 3.80 x 1024 molecules of NH3? (5 points)
74.8 grams
107 grams
89.4 grams
101 grams
Answer: 107 grams
Explanation: got it right on the test
The mass of a sample of f NH₃ containing 3.80 x 10²⁴ molecules of NH₃ is 107.27 grams.
What is a molecule?A molecule is a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
6.02214076 × 10²³ molecules constitute 1 mole of NH₃
3.80 x 10²⁴ molecules constitutes of = 6.31 moles
1 mole of NH₃ = 17 gm
11.19 mole will be = 17 X 6.31
= 107.27 grams
Therefore the mass of a sample of NH₃ containing 3.80 x 10²⁴ molecules of NH₃ is 107.27 grams.
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A trophic level is a number that tells you the position an organism occupies in a food chain or food pyramid.
True
False
Answer:
true
Explanation:
Where and why the U.S. acid rain damage is the greatest.
Answer:
Some acid rain occurs naturally, but sulfur dioxide and nitrogen oxide emissions from smokestacks combine with rain to make sulfuric and nitric acid in amounts that harm.
Explanation:
112 g of aluminum carbide react with 174 g water to produce methane and aluminum hydroxide in the reaction shown below.
2 Al4C3(s) + 12 H2O(l) → 3 CH4(g) + 4 Al(OH)3(s)
If aluminum carbide is the limiting reactant, how many moles of the excess reactant are left over
a
37.3 mol
b
4.68 mol
c
7.33 mol
d
131.94 mol
Answer: 4.999 moles of excess reactant will be left over.
Explanation:
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
Given mass of aluminium carbide = 112 g
Molar mass of aluminium carbide = 143.96 g/mol
Putting values in equation 1:
[tex]\text{Moles of aluminium carbide}=\frac{112g}{143.96g/mol}=0.778mol[/tex]
For the given chemical reaction:
[tex]2Al_4C_3(s)+12H_2O(l)\rightarrow 3CH_4(g)+4Al(OH)_3(s)[/tex]
By the stoichiometry of the reaction:
2 moles of aluminium carbide reacts with 12 moles of water
So, 0.778 moles of aluminium carbide will react with = [tex]\frac{12}{2}\times 0.778=4.668 mol[/tex] of water
Given mass of water = 174 g
Molar mass of water = 18 g/mol
Putting values in equation 1:
[tex]\text{Moles of water}=\frac{174g}{18g/mol}=9.667mol[/tex]
Moles of excess reactant (water) left = 9.667 - 4.668 = 4.999 moles
Hence, 4.999 moles of excess reactant will be left over.