Which of these is true concerning an endothermic reaction? *
When a system absorbs more energy than it releases and has a negative AH.
When a system absorbs more energy than it releases and has a positive AH.
When a system releases more energy than it absorbs and has a negative AH.
When a system releases more energy than it absorbs and has a positive AH.
Answer:
A system absorbs more energy than it releases and has a positive AH
Explanation:
Answer:
Explanation:
Endothermic (endo = into + thermic = heat) means that heat energy is going into a system.
The products will have more energy than the reactants and ΔH will be positive.
A is wrong, because ΔH is positive.
C and D are wrong, because the system absorbs more energy than it releases.
Chloroform is a commonly used anesthetic with a density of 1.483 g/mL. Determine the volume of chloroform needed to deliver a 9.37 g sample of the anesthetic
Answer:
The correct answer is 6.32 ml
Explanation:
We have the following data:
Mass : m = 9.37 g
Density : d= 1.483 g/mL
The density a substance is equal to the mass of the substance divided into its volume. So, we calculate the volume (V) of chloroform from the mass and density as follows:
[tex]d=\frac{m}{V}[/tex] ⇒ [tex]V = \frac{m}{d} = \frac{9.37 g}{1.483 g/ml} = 6.32 ml[/tex]
What is the overall reduction potential for the reaction Agt (aq) + Cu(s)——>Ag(s) + Cu2+ (aq)?
-0.46 V
+0.46 V
+0.57 v
+1.14V
Answer:
it should be +0.46 :)
Explanation:
I just took the test and got it right.
Answer:
I think it's +1.14 V, but don't take my word for it..
what is the reason that dogs shed
does the temperature of water affect the time it takes a sugar cube to dissolve
Answer:
Dogs naturally lose old or damaged hair by shedding. Although shedding. and yes
As SCUBA divers go deeper underwater, the pressure from the weight of all the water above them increases tremendously
which compresses the gases in their blood. What happens to the volume of gas in their blood as the diver rises quickly to
the surface?
A As a diver rises, the pressure on their body increases which allows the volume of the gas to decrease.
B. As a diver rises, the pressure on their body decreases which allows the volume of the gas to decrease.
c. As a diver rises, the pressure on their body increases which allows the volume of the gas to increase.
D. As a diver rises, the pressure on their body decreases which allows the volume of the gas to increase.
Answer:
b
Explanation:
Using the equation below, calculate the approximate moles of oxygen gas (O2) required to completely react with 719.68 moles of aluminum (Al). 4Al (s) + 3O2(g) -----> 2Al2O3(s)
Answer:
539.76 moles of O₂
Explanation:
Equation of reaction:
4Al + 3O₂ → 2Al₂O₃
From the equation of reaction above, 4 moles of Al will react with 3 moles of O₂
We can use mole-concept to find the number of moles of O₂.
4 moles of Al = 3moles of O₂
719.68 moles of Al = x moles of O₂
X = (3 × 719.68) / 4
X = 2159.04 / 4
X = 539.76 moles
539.76 moles of O₂ will react with 719.68 moles of Al
Answer:
[tex]n_{O_2}=959.57molO_2[/tex]
Explanation:
Hello,
In this case, given the reaction:
[tex]4Al (s) + 3O_2(g) \rightarrow 2Al_2O_3(s)[/tex]
Since aluminum and oxygen are in a 4:3 molar ratio, we compute the moles of oxygen that completely react as shown below:
[tex]n_{O_2}=719.68molAl*\frac{3molO_2}{4molAl} \\\\n_{O_2}=959.57molO_2[/tex]
Best regards.
In CaSO4, the oxidation number of Ca is
that of S is
and that of O is
Answer: In CaF2, the oxidation number of Ca is +2
, and that of F is -1
. In H2SO4, the oxidation number of H is +1
, that of S is +6
, and that of O is -2
. In CaSO4, the oxidation number of Ca is +2
, that of S is +6
, and that of O is -2
. In HF, the oxidation number of H is +1
, and that of F is -1
what started the wildfires
Answer:
It is a typical fires that started out of a lightning strike, or people carelessly starting it, or accidentally, or even arson, that went un-noticed and got out of hand.
Answer:
Explanation:
Forest fires always start by one of two ways - naturally caused or human caused. Natural fires are generally started by lightning, with a very small percentage started by spontaneous combustion of dry fuel such as sawdust and leaves. On the other hand, human-caused fires can be due to any number of reasons.
How might an antioxidant prevent another element from gaining or losing an electron?
Answer:
An antioxidant helps in the mopping up and elimination of free radicals and a common example is Glutathione. Oxidation reactions Involves the transfer of electrons or addition of oxygen to a substance.
Antioxidants help in decreasing or prevention of the oxidation of the molecules due to free radicals being formed which causes damage in the cells of animals.
What is the oxidation half-reaction for this unbalanced redox equation? cr2o72– + fe2+ → cr3+ + fe3+ cr3+ → cr2o72– cr2o72– → cr3+ fe3+ → fe2+ fe2+ → fe3+?
Answer:
6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e
Explanation:
The balanced oxidation half equation is;
6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e
A redox reaction is actually an acronym for oxidation-reducation reaction. Since the both reactions are complementary, there can't be oxidation without reduction and there can't be reduction without oxidation.
The main characteristic of redox reactions is that electrons are transferred in the process. The number of electrons transferred is usually deduced from the balanced reaction equation. For this reaction, the balanced overall reaction equation is;
Cr2O7^2–(aq) + 6Fe^2+(aq) +14H^+(aq)→ 2Cr^3+(aq) + 6Fe^3+ (aq) + 7H2O(l)
It is clear from the equation above that six electrons were transferred. Thus six Fe^2+ ions lost one electron each in the oxidation half equation as shown in the balanced oxidation half equation above.
Which options identify what the arrows in the diagram
represent? Check all that apply.
D atoms
elements
energy
gas
particles
Answer:
D
Explanation:
Why does dew form on the outside of your glass filled with ice cold water?
How many grams of H2 can be produced from the reaction of 11.50 g of sodium with an excess of water? The equation for the reaction is 2 Na + 2 H2O -> 2 NaOH + H2 Ans: 0.504 2 g H2 I would like to know how to solve this problem, the teacher gave me the answer but I am unsure how to solve it thanks!
Answer:
[tex]m_{H_2}=0.504gH_2[/tex]
Explanation:
Hello,
In this case, since the reaction is:
[tex]2 Na + 2 H_2O \rightarrow 2 NaOH + H_2[/tex]
We notice that since there is an excess of water, we can directly compute the yielded grams of hydrogen by using the following stoichiometric procedure, considering the 2:1 molar ratio between sodium and hydrogen (notice the 2 before the sodium and the 1 before the hydrogen at the chemical reaction) and that gaseous hydrogen has a molar mass of 2 g/mol:
[tex]m_{H_2}=11.50gNa*\frac{1molNa}{22.98gNa} *\frac{1molH_2}{2.02molNa} *\frac{2gH_2}{1molH_2} \\\\m_{H_2}=0.504gH_2[/tex]
Best regards.
Answer:
0.503g of H₂ are produced
Explanation:
Based on the chemical reaction:
2 Na + 2 H₂O → 2 NaOH + H₂
2 moles of Na react with 2 moles of water to produce 2 moles of NaOH and 1 mole of H₂
11.50g of Na -limiting reactant, molar mass 22.99g/mol- are:
11.50g× (1mol / 22.99g) = 0.500 moles of Na.
As 2 moles of Na produce 1 mole of H₂:
0.500 moles of Na × (1 mole H₂ / 2 moles Na) = 0.250 moles of H₂
As molar mass of H₂ is 2.01g/mol:
0.250 moles of H₂ × (2.01g / 1mol) = 0.503g of H₂ are produced
Why is fusion not used to generate electrical power ?
Answer:
Fusion doesn't produce runway chain reactions the way fission can, so there's no need to worry about meltdowns.
How many milliliters of 0.2 M NaOH are required to exactly neutralize 40 milliliters of 0.1 M HCl?
A) 10
B) 20
C) 40
D) 80
Answer:
Option B. 20mL
Explanation:
Step 1:
Data obtained from the question.
Volume of base (Vb) =..?
Molarity of base (Mb) = 0.2M
Volume of acid (Va) = 40mL
Molarity of acid (Ma) = 0.1M
Step 2:
The balanced equation for the reaction.
HCl + NaOH —> NaCl + H2O
From the balanced equation above, the following were obtained:
Mole ratio of the acid (nA) = 1
Mole ratio of the base (nB) = 1
Step 3:
Determination of the volume of base, NaOH needed for the reaction. This is illustrated below:
MaVa/MbVb = nA/nB
0.1 x 40 / 0.2 x Vb = 1
Cross multiply
0.2 x Vb = 0.1 x 40
Divide both side by 0.2
Vb = 0.1 x 40 / 0.2
Vb = 20mL
Therefore, the volume of the base is 20mL.
What is the compounds of AICI3 and H+
Answer:
Aluminium Chloride and Hyrdron, also known as proton/
Explanation:
How many grams of KF are in 2 liters of a 3.0 M solution of KF
Answer:
mass ( g ) = 348 g
Explanation:
First you know : M = mole / volume (L)
in question you have the M and V and the formula of SUBSTANCE ( KF )
first you get the number of mole from equation above
so 3 = no of mole / 2
no of mole = 3 × 2 = 6 moles
and the moles equation is no of moles = mass ( g ) / molecular weight ( g/mole )
so you have already calculate the moles and you can know the MW from the Question
Mw of KF = 39 + 19 = 58
so n = mass / MW
so 6 = mass / 58
mass ( g ) = 348 g
GOOD LUCK
Balance equation: _NO + _H2O = _NH3 + _O2
Answer:
4NO + 6H2O = 4NH3 + 5O2
Explanation:
Think about it this way: there are 4N's 4O's and 12H's and 10O's on both sides that's what makes it balanced
Hope this helps :)
Describe the benefits of using nanoparticles instead of other, larger technology.
Answer:
it has a huge surface-to-volume ratio, very high porosity and completely different physiochemical properties.
Explanation:
idk if the answer is good !
sorry
Is the same reactant always the limiting reactant?
5) Usted empuja muy fuerte un escritorio pesado e intenta moverlo. Usted efectúa trabajo sobre el escritorio: a.- Ya sea que lo mueva o no, siempre y cuando usted ejerza una fuerza. B.- Sólo si el escritorio se mueve. C.- Sólo si el escritorio no se mueve. D.- Nunca; el escritorio hace trabajo sobre usted. E.- Ninguna de las anteriores. ME AYUDAN PORFA?
Answer:
5) You push hard on a heavy desk and try to move it. You do work on the desk: A.- Whether you move it or not, as long as you exert a force. B.- Only if the desktop moves. C.- Only if the desktop does not move. D.- Never; the desk does work on you. E.- None of the above. CAN YOU HELP ME?
B.- Only if the desktop moves.
Explanation:
No work is done if a force is exerted but no displacement occurs. A force perpendicular to the displacement does no generate work.
There are 0.55 moles of carbon dioxide gas in a 15.0 L container. This container is at a temperature of 300 K. What is the pressure of the gas inside the container? Use 8.31 L*kPa/mol*K for the gas constant.
A.)760 mm Hg\
B.) 271 kPa
C.) 2 atm
D.) 91.4 kPa
Answer:
[tex]\large \boxed{\text{D.) 91 kPa}}[/tex]
Explanation:
We can use the Ideal Gas Law — pV = nRT
Data:
V = 15.0 L
n = 0.55 mol
T = 300 K
Calculation:
[tex]\begin{array}{rcl}pV & =& nRT\\p \times \text{15.0 L} & = & \text{0.55 mol} \times \text{8.31 kPa$\cdot$ L$\cdot$K$^{-1}$mol$^{-1}\times$ 300 K}\\15.0p & = & \text{1370 kPa}\\p & = & \textbf{91 kPa}\end{array}\\\text{The pressure in the container is $\large \boxed{\textbf{91 kPa}}$}[/tex]
Which one is it? Please help
Answer:
Chemical properties can be tested without changing the substance
Explanation:
In a titration how much 0.50 M HCl is needed to neutralize 1 liter of a 0.75 M solution of NaOH?
1.5 L
2.25 L
1.0 L
0.75 L
Answer:
1.5 L
Explanation:
Step 1:
The balanced equation for the reaction. This is given below:
HCl + NaOH —> NaCl + H2O
From the balanced equation above, The mole ratio of the acid (nA) = 1
The mole ratio of the base (nB) = 1
Step 2:
Data obtained from the question. This includes the following:
Molarity of acid (Ma) = 0.5M
Volume of acid (Va) =..?
Volume of base (Vb) = 1L
Molarity of base (Mb) = 0.75M
Step 3:
Determination of the volume of the acid needed for the reaction.
Using the formula:
MaVa/MbVb = nA/nB
The volume of the acid needed for the reaction can be obtained as follow:
0.5 x Va / 0.75 x 1 = 1
Cross multiply
0.5 x Va = 0.75 x 1
Divide both side by 0.5
Va = 0.75 /0.5
Va = 1.5 L
Therefore, the volume of the acid, HCl needed for the reaction is 1.5L
What do half-reactions show?
O
A. They show the oxidatign and reduction halves of a reaction.
B. They show only the electrons that are transferred in a reaction.
C. They show the reactant half and the product half of a reaction.
D. They show the ionic equation and the spectator ions of a reaction.
Answer: A. They show the oxidation and reduction halves of a reaction.
Explanation:
Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.
For a redox reaction: [tex]A+B^+\rightarrow A^++B[/tex]
Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.
oxidation half at anode : [tex]A\rightarrow A^++e^-[/tex]
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.
reduction half at cathode: [tex]B^++e^-\rightarrow B[/tex]
Half-reactions show the oxidation and reduction halves of a reaction. The correct answer is option A.
Oxidation is a chemical reaction that involves the loss of electrons by a molecule, atom, or ion. This process results in an increase in the oxidation state of the species undergoing oxidation.
Half-reactions are used to show the oxidation and reduction half of the reaction separately, which makes it easier to balance the overall reaction and to identify the species that are being oxidized and reduced.
In a half-reaction, the species that is being oxidized loses electrons and is called the reducing agent, while the species that is being reduced gains electrons and is called the oxidizing agent. By balancing the number of electrons transferred in each half-reaction, it is possible to balance the overall redox reaction.In conclusion, half-reactions are used to show the oxidation and reduction halves of a redox reaction separately. Option A is the correct answer.
Learn more about oxidation here:
https://brainly.com/question/13182308
#SPJ6
Help me, I don’t understand
Answer:
option c
Explanation:
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What mass of water will be collected if 20.0
grams of hydrogen are consumed
2H2+O2--->2H2O
358g
179g
44.7g
Or 89.4g
Answer: 179 of [tex]H_2O[/tex] will be produced.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} H_2=\frac{20.0g}{2.01g/mol}=9.95moles[/tex]
[tex]2H_2+O_2(g)\rightarrow 2H_2O[/tex]
According to stoichiometry :
2 moles of [tex]H_2[/tex] give = 2 moles of [tex]H_2O[/tex]
Thus 9.95 moles of [tex]H_2[/tex] will require=[tex]\frac{2}{2}\times 9.95=9.95moles[/tex] of [tex]H_2O[/tex]
Mass of [tex]H_2O=moles\times {\text {Molar mass}}=9.95moles\times 18g/mol=179g[/tex]
Thus 179 of [tex]H_2O[/tex] will be produced.
I am a subatomic particle
that is positively charged what am I?
The right answer is Proton.
Additional Information:
There are three types of subatomic particles. They are:
ProtonElectronNeutronProton is a positively charged particle,Electron is negatively charged particle and Neutron is charge less.
Hope it will be helpful to you...
What is the % of each element in Ni3{PO4) 2 ?
Answer:
nickel 48.1063%
Phosphorus 16.9245%
Oxygen 34.9692%
The percent composition of each element like nitrogen, oxygen and phosphorous in Ni₃(PO₄)₂ are 48.03%, 34.97% and 16.93% respectively.
How do we calculate % composition?Percent composition of any element present in any compound will be calculated as:
% comosition = (Mass of element / Mass of compound)×100%
Mass of Ni₃(PO₄)₂ compound = 366.02 g/mol
Molar mass of 3 Nitrogen atoms = 3×58.6 = 175.8 g/mol
Moar mass of 2 Phosphorous atoms = 2×31 = 62 g/mol
Moar mass of 8 Oxygen atoms = 8×16 = 128 g/mol
% comosition of Nitrogen = (175.8/366.02)×100% = 48.03%
% comosition of Oxygen = (128/366.02)×100% = 34.97%
% comosition of Phosphorous = (62/366.02)×100% = 16.93%
Hence % composition of nitrogen, oxygen and phosphorous is 48.03%, 34.97% and 16.93% respectively.
To know more about percent composition, visit the below link:
https://brainly.com/question/21044245
Which correctly defines a basic solution? A. [H+] is not present. B. [H+] is equal to [OH−]. C. [H+] is less than [OH−]. D. [H+] is greater than [OH−].
Answer: A basic solution is defined as a solution which has more hydroxide (OH-) ions than hydronium ions (H+)
