Explanation:
83.6-24.2= 59.4 which is the change in heat
Using the Kf value of 1.2×109 calculate the concentration of Ni2+(aq) and Ni(NH3)62+ that are present at equilibrium after dissolving 1.47 gNiCl2 in 100.0 mL of NH3(aq) solution such that the equilibrium concentration of NH3 is equal to 0.20 M.
Express your answers in moles per liter to two significant figures separated by a comma.
This problem is describing the equilibrium whereby the formartion of a complex is attained when 1.47 g of nickel(II) chloride is dissolved in 100.0 mL of ammonia so that the latter's equilibium concentration is 0.20 M. Thus, it is asked to calculate the equilibrium concentrations of both nickel(II) ions and that of the complex.
Firstly, we can write out the chemical equation to be considered:
[tex]Ni^{2+}+6NH_3\rightleftharpoons Ni(NH_3)_6^{2+}[/tex]
Next, we can calculate the initial concentration of nickel(II) ions by using the concept of molarity:
[tex][Ni^{2+}]=\frac{1.47gNiCl_2*\frac{1molNiCl_2}{129.6g}*\frac{1molNi^{2+}}{1molNiCl_2} }{0.1000L}=0.113M[/tex]
Afterwards, we set up an equilibrium expression for this chemical reaction:
[tex]Kf=\frac{[Ni(NH_3)_6^{2+}]}{[Ni^{2+}][NH_3]^6}[/tex]
Which can be written in terms of the reaction extent, [tex]x[/tex]:
[tex]Kf=\frac{x}{(0.113-x)(0.2)^6}[/tex]
Now, for the calculation of [tex]x[/tex], we plug in Kf, and solve for it:
[tex]1.2x10^9=\frac{x}{(0.113-x)(0.2)^6}\\\\1.2x10^9=\frac{x}{(0.113-x)(6.4x10^{-5})}\\\\7.68x10^4(0.113-x)=x\\\\x=0.112999 M[/tex]
Which is about the same to the initial concentration of nickel(II) ions because the Kf is too large.
Thus, the required concentrations at equilibrium are about:
[tex][Ni(NH_3)_6^{2+}]=0.113M[/tex]
[tex][Ni^{2+}]=0M[/tex]
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https://brainly.com/question/13043707After spending some time in the stomach, the food is sent to the blank
Answer:
the small intestine where nutrients are absorbed.
Help !
Student A uses 3N of force to move a cart 5 meters in 10 seconds. Student B uses 6N of force to move the same cart the same distance in 5 seconds. Which student did more work? Which student used more power? Use evidence and explain your answersss
Work = force x distance
Power = work/time
Work is said to be done if the force applied to a body causes the body to move through a distance.
Student B used more work and power
Workdone = Force * Distance
For student A:
Force = 3N
distance = 5meters
Time taken = 10 secs
Workdone by Student A = 3 * 5
Workdone by student A = 15Nm
Power used up = workdone/time
Power used up = 15/10
Power used up = 1.5 Watts
For student B:
Force = 6N
distance = 5meters
Time taken = 5 secs
Workdone by Student A = 6 * 5
Workdone by student A = 30Nm
Power used up = workdone/time
Power used up = 30/5
Power used up = 6 Watts
This shows that student B used more work and power
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How many federal agencies are responsible for managing land resources in the United States?
2
4
ОООО
6
10
The answer would be 4.
The agencies are:
Department of Agriculture's Forest Service (AFS)
Department of the Interior's Bureau of Land Management (BLM)
Fish and Wildlife Service (FWS)
National Park Service (NPS)
These four agencies cover around 95% of the land and are the only federal agencies.
I learned about these agencies in school.
A mixture is made of 40 ml of salt water to 200 ml of solution. What percent of the solution is salt water?
Answer:
16.7%
Explanation:
40 ml of salt water + 200 ml of solution = 240 ml
40/240 = 4/24 = 1/6=16.7%
How can you include osmosis in animal cell
10. Select the more polar bond in each of the following pairs: a) C and N or C and o b) N and F or N and O.
Grace wanted to find out the best conditions for growing lettuce plants.
She took 4 trays and planted 8 lettuce plants in each.
The results of her investigation are shown below.
How many days did the investigation last?
Use the table to help you.
Explanation:
the investigation lasts for 7 days !
hope this helps you.
Can you help me with these questions?
I already did 3 which are the highlighted ones. Help me with the ones that are not.
A metal (FW 341.1 g/mol) crystallizes into a body-centered cubic unit cell and has a radius of 1.74 Angstrom. What is the density of this metal in g/cm3
This problem provides the molar mass and radius of a metal that has an BCC unit cell and the density is required.
Firstly, we consider the formula that relates molar mass and also includes the Avogadro's number and the volume of the unit cell:
[tex]\rho =\frac{Z*M}{V*N_A}[/tex]
Whereas Z stands for the number of atoms in the unit cell, M the molar mass, V the volume and NA the Avogadro's number. Next, since BCC is able to hold 2 atoms and M and NA are given, we calculate the volume of the atom in the unit cell given the radius in meters:
[tex]V=a^3=(\frac{4R}{\sqrt{3} } )^3=(\frac{4*1.74x10^{-10}m}{\sqrt{3} } )^3=6.49x10^{-29}m^3[/tex]
And finally the required density in g/cm³:
[tex]\rho =\frac{2*341.1g/mol}{6.49x10^{-29}m^3\frac{m^3}{atom} *6.022x10^{23}\frac{atom}{mol} } =17455257.8g/m^3\\\\\rho=17.5g/cm^3[/tex]
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PLS HELP= BRAINLIEST AND POINTS
Question 11 pts
What is the term for the "invisible force" that holds you to Earth's surface?
Group of answer choices
gravity
mass
attraction
matter
Flag question: Question 2
Question 21 pts
Once an object is in motion, what type of energy is being used?
Group of answer choices
kinetic energy
gravity
potential energy
Flag question: Question 3
Question 31 pts
The Moon's mass is lower than that of Earth, thus its gravity is ____ Earth’s gravity.
Group of answer choices
less than
more than
the same as
Flag question: Question 4
Question 41 pts
When you roll a ball across a rug, what slows it to a stop?
Group of answer choices
Friction resists the ball’s forward motion.
The rug doesn’t have enough momentum to keep the ball rolling.
The rug doesn’t have enough force to keep the ball rolling.
The ball isn’t moving fast enough.
Flag question: Question 5
Question 51 pts
A championship swimmer swims 20 meters in 10 seconds. What is his speed?
Group of answer choices
20 m/s
2.0 m/s
0.5 m/s
200 m/s
Flag question: Question 6
Question 61 pts
Without an unbalanced force, an object will ____.
Group of answer choices
change its direction
maintain its velocity
stop moving altogether
change its speed
Flag question: Question 7
Question 71 pts
Which of the following indicates how fast something is moving?
Group of answer choices
speed
gravity
force
inertia
Flag question: Question 8
Question 81 pts
Which of Newton's laws is also known as the law of inertia?
Group of answer choices
Newton's third law
Newton's first law
Newton's second law
Flag question: Question 9
Question 91 pts
Which object would need the greatest force to overcome its inertia?
Group of answer choices
a sports car
a bicycle
a dump truck
a tennis ball
Flag question: Question 10
Question 101 pts
Which of the following is described by the change in an object’s position?
Group of answer choices
force
position
motion
Explanation:
gravity
kinetic energy
less than
friction resists the ball's movement
2.0 m/s
change its direction
speed
newton's first law
dump truck
position
Answer:
Q1 - Gravity
Q2 - Kinetic Energy
Q3 - Less than
Q4 - Friction resists the ball's forward motion
Q5 - 2 m/a
Q6 - Change its speed
Q7 - Speed
Q8 - Second law
Q9 - a dump truck
Q10 - motion
I am not sure about some answers but I answered all questions.
If 5 g of sodium chloride saturates 12.5 g of water at 10 °C, what mass of sodium chloride would saturate 50 g of water at constant temperature?
Explanation:
since 5g saturates 12.5g of water at 10°c
so......x would saturate 50g of water at 0°c
then you can cross multiply
Learning Task 2: Read each statement or question below carefully and fill in the blank(s) with the best answer by choosing the words inside the box. Write your answers in a separate sheet of paper. cation 1 -ide -ine nonmetals O ion ionic compound anion metals root name 1. Any atom or molecule with a net charge, either positive or negative, is known as en 2. An atom that gains one extra electron forms an with a 1- charge. 3. A positive ion, called a is produced when one or more electrons are lost from a neutral atom. 4. Unlike a cation, which is named for the parent atom, an anion is named by taking the of the atom and changing the ending. 5. The name of each anions is obtained by adding the suffix to the root of the atom name. 6. The always form positive ions. 7. on the other hand, form negative ions by gaining electrons. 8. It is very important to remember that a chemical compound must have a net charge of
Silver can be plated out of a solution containing Ag+ according to the half-reaction
Ag+(aq)+e−→Ag(s)
How much time (in minutes) does it take to plate 19 g of silver using a current of 3.4 A ?
Answer:
Approximately [tex]83[/tex] minutes.
Explanation:
Look up the relative atomic mass of [tex]\rm Ag[/tex]: [tex]M({\rm Ag}) = 107.868\; \rm g \cdot mol^{-1}[/tex].[tex]\begin{aligned}Q &= e\, (n(e)) \\ &\approx 1.602 \times 10^{-19}\; \rm C \times 1.06 \times 10^{23} \\ &\approx 1.6987 \times 10^{4}\; \rm C \end{aligned}[/tex]/.
Avogadro's number: [tex]N_A \approx 6.02 \times 10^{23}\; \rm mol^{-1}[/tex].
Elementary charge: [tex]e \approx 1.602 \times 10^{-19}\; \rm C[/tex].
Calculate the quantity of [tex]\rm Ag[/tex] atoms to reduce:
[tex]\begin{aligned}& n({\rm Ag}) \\ &= \frac{m({\rm Ag})}{M({\rm Ag})} \\ &= \frac{19\; \rm g}{107.868\; \rm g \cdot mol^{-1}} \\ & \approx 0.176\; \rm mol\end{aligned}[/tex].
By the equation, it takes one electron to reduce every [tex]\rm Ag[/tex] atom. Thus, the number of electrons required to reduce [tex]0.176\; \rm mol[/tex] of [tex]\rm Ag\![/tex] atoms would be:
[tex]n(e) = n({\rm Ag}) \approx 0.176\; \rm mol[/tex].
[tex]\begin{aligned}N(e) &= n(e) \cdot N_{A}. \\ &\approx 0.176\; \rm mol \times 6.02 \times 10^{23}\; \rm mol^{-1} \\ & \approx 1.06 \times 10^{23}\end{aligned}[/tex].
Calculate the amount of charge (in coulombs) in that many electrons:
[tex]\begin{aligned}Q &= e\, (n(e)) \\ &\approx 1.602 \times 10^{-19}\; \rm C \times 1.06 \times 10^{23} \\ &\approx 16987.1 \; \rm C \end{aligned}[/tex].
A current of [tex]1\; \rm A[/tex] carries a charge of [tex]1\; \rm C[/tex] every second. Thus, the amount of time required for this current to carry that much electron would be:"
[tex]\begin{aligned}t &= \frac{Q}{I} \\ &\approx \frac{16987.1\; \rm C}{3.4\; \rm A} \\ &\approx 83.3\; \rm s \\ &\approx 5.00\times 10^{3}\; \rm s \\ &\approx 83\; \text{minutes} \end{aligned}[/tex].
Which statement best describes the effect of radioactive decay on a nucleus?
When radioactive decay occurs, the original nucleus splits into daughter nuclei and the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.
Unstable nuclei often undergo radioactive decay. In a radioactive decay, the unstable nucleus is broken up into other nuclei. Usually, the nuclei formed during radioactive decay are smaller in mass compared to the original nucleus.
Also, the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.
The effect is that the nucleus changes into the nucleus of one or more other elements. These daughter nuclei have a lower mass and are more stable (lower in energy) than the parent nucleus.
To what pH should you adjust a standard hydrogen electrode to get an electrode potential of -0.128 V ? (Assume that the partial pressure of hydrogen gas remains at 1 atm.) Express your answer using two decimal places.\
The pH of the standard hydrogen electrode that has electrode potential of -0.128 V is 4.3.
The equation of the hydrogen electrode is;
2H^+(aq) + 2e ⇄ H2(g)
The standard electrode potential of hydrogen is 0.00 V
Using the Nernst equation;
Ecell = E°cell - 0.0592/n log Q
Now;
E°cell = 0.00 V
n = 2
Q = 1/[H^+]
-0.128 = 0.00 - 0.0592/2 log 1/[H^+]
-0.128 = 0.00 - 0.0296 log 1/[H^+]
-0.128 = - 0.0296 log 1/[H^+]
-0.128/ - 0.0296 = log 1/[H^+]
1/[H^+] = Antilog (4.32)
[H^+] = 4.79 × 10^-5
Now;
pH = -log[H^+]
pH = -log (4.79 × 10^-5)
pH = 4.3
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How many moles of NaOH are present in 12.0 mL of 0.110 NaOH?
Moles: ___________
Answer:
0.00132moles
Explanation:
1000ml of NaOH contain 0.110 moles
12ml of NaOH contain (12*0.110)/1000 moles
= 0.00132 moles
You have three gases in a mixture where P1= 100 kPa, P2 = 50 kPa, and P3 = 75
kPa. What is the total pressure of the gas mixture?
A. 225 kPa
B. 25 kPa
C. 75 kPa
D. None of the above
Answer:
Ptotal=P1+P2+… +Pn. + P nExplanation:
its c
A student performs a titration of 51.0 mL of a phosphoric
acid (H PO) solution of unknown concentration with a
standardized 1.25 M NaOH solution. The titration requires
26.2 mL of base to reach the third equivalence point. What is
the concentration of the H3PO4
solution?
From the information available in the question, the concentration of the acid is 0.21 M.
H3PO4(aq) + 3NaOH(aq) -----> Na3PO4(aq) + 3H2O(l)
Volume of acid(VA) = 51.0 mL
Concentration of acid (CA) = ?
Volume of base (VB) = 26.2 mL
Concentration of base (CB) = 1.25 M
Number of moles of acid (NA) = 1
Number of moles of base (NB) = 3
Using the formula;
CAVA/CBVB = NA/NB
CAVANB = CBVBNA
CA = CBVBNA/VANB
CA = 1.25 M × 26.2 mL × 1/51.0 mL × 3
CA = 0.21 M
The concentration of the acid is 0.21 M.
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Question 1
Which of the following describes the movement of molecules in a solid?
O Molecules are stationary.
O Molecules vibrate in fixed positions.
O Molecules move fast enough to change position.
O Molecules move freely.
Please help ASAP!!!
Answer:
Molecules vibrate in a fixed position.
Explanation:
first one is just wrong.
third is liquid
fourth is gas
Which two types of information are written in an element's box in the periodic table?
I think it is B,D
Answer:
Yes it is B,D.
Explanation:
Each box represents an element and contains its atomic number, symbol, average atomic mass, and (sometimes) name. The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups.
Each element can be indentified by the number of _______ found in its nucleus, which also equals the elements _______ _______.
How many grams of sodium acetate NaCH3COO, , must be dissolved to prepare 200. mL of a 0.216 M aqueous solution of the salt? g
Answer:
Explanation:
You have to find the mass in the mole before the molarity and then in the mole.
Determine how many grams of Al(OH)3 will be required to neutralize 216 mL of 0.367 M HCl according to the reaction:
3HCl + Al(OH)3 > AlCl3 + 3H20
mol = conc × v
= 0.367 × 0.216
= 0.0792 mol HCl
3 mol HCl = 1 mol Al(OH)3
0.0792 mol HCl = x
x = 0.0792/3 × 1
= 0.0264 mol Al(OH)3
Al(OH)3 = 27 + 3(16 +1) = 78 g/mol
mass = mol x molar mass
= 0.0264 × 78
= 2.0592 g
I don't know if it's correct
6) 0.5 moles of gas is kept at 2.0 L of volume and 0.75 atm of pressure. What is the temperature of the gas in K?
Answer:
310K
Explanation:
Rearrange PV=nRT to get T=PV/nR
T=(2.0L)(0.75atm)/(0.5mol)(0.08206)
=36.5 or 37
add 273 for K to get
310
4
Fe
(
III
)
+
3
O
2
→
2
F
e
2
O
3
Answer:
230293
Explanation:
4fe(lll) + 3o2 2o2 2Fe 2O3 + 230293
PLEASE HELPPPPPPPPPPPPPPPP
in a certain reaction, Fe and O2 combine to form iron (iii) oxide. 14.7 moles of Fe and 13.0 moles of O2 are placed in a container and the reaction proceeds iwth 100% yield. which is the excess reactant
Answer:
Fe is the excess reactant
Reaction yields are the amount of the reactant and the products of a chemical reaction. In the reaction between iron and oxygen, iron is the excess agent.
What is excess reactant?The reactant present in an extra quantity than the other reactant in a chemical reaction which reacts with the limiting reactant is called an excess reactant.
In a reaction mixture, the excess reactant is present even when the limiting agent is completely consumed.
The chemical reaction between iron and oxygen is shown as,
[tex]\rm 4 Fe(s) + 3 O_{2}(g) \rightarrow 2 Fe_{2}O_{3}[/tex]
From the reaction, it can be said that oxygen is a limiting reagent that limits the formation of iron (iii) oxide.
Therefore, iron is an excess reactant.
Learn more about excess and limiting reagents here:
https://brainly.com/question/13285193
Which of the following best describes the scientific exploration of the atom?
Sodium hydroxide neutralises hydrochloric acid as shown in the equation:
NaOH(aq) + HCl(aq) i NaCl(aq) + H2O(l)
(4)
dm3
(3)
The student found that 27.20 cm3 of 0.100 moles per dm3 sodium hydroxide neutralised 5.00 cm3 of hydrochloric acid.
Calculate the concentration of the hydrochloric acid in moles per dm3.
Give your answer to three significant figures.
Explanation:
Mole ratio of NaOH : HCl = 1: 1
Moles of NaOH used = 0.1 mol/1000 cm3 × 27.20 cm3
= 2.72 × 10^-3 mol
Therefore moles of HCl used is also 2.72 × 10^-3 mol
So concentration of HCl can be found by dividing the no.of moles of HCl by the volume of HCl as follows
2.72 × 10^-3 mol/ 5cm3
1000cm3 = 1dm3
Therefore,
1cm3 = 1/1000 dm3
5cm3 = 5/1000 dm3
HCl conc. = 2.72 × 10^-3 mol/ 5×10^-3 dm3
= 0.544 moldm-3