Which step is part of a scientific investigation?
O designing a solution
O implementing the solution
O evaluating the solution
O communicating the findings
what mass of calcium chloride will be produced from 3.750 moles of hcl reacting with ca(oh)2
Answer:
208.125g
Explanation:
Given parameters:
Number of moles of HCl = 3.75moles
Unknown:
Mass of CaCl₂ that will be produced = ?
Solution:
The reaction equation is given as:
2HCl + Ca(OH)₂ → CaCl₂ + 2H₂O
Now, to find the mass of CaCl₂, we have to work from the known to the unknown.
The known specie here is the number of moles of HCl;
2 mole of HCl will produce 1 mole of CaCl₂
3.75moles of HCl will produce [tex]\frac{3.75}{2}[/tex] = 1.875moles
The mass of CaCl₂;
Mass of CaCl₂ = number of moles of CaCl₂ x molar mass
Molar mass of CaCl₂ = 40 + 2(35.5) = 111g/mol
Mass of CaCl₂ = 1.875 x 111 = 208.125g
If the stack of bricks on the right has a mass of 240 kg, approximately what is the mass of the stack of bricks on the left?
A.
2400 kg
B.
720 kg
C.
320 kg
D.
480 kg
Answer:
720
Explanation: study island
Answer:
720
Explanation:
The ethyl acetate solution containing the mixture used in this experiment had a concentration of 20.0 g/L of benzoic acid. 1. Recovery of benzoic acid:
Answer:
The correct answer is "[tex]\frac{0.65}{V} \ percent[/tex]".
Explanation:
The given values are:
[tex]M_r=0.130 \ g[/tex]
[tex]M_o=20 \ g/L\times V(L)[/tex]
[tex]=20 \ V[/tex]
As we know,
⇒ [tex]Recovery \ percent=\frac{Amount \ of \ substance \ recovered}{Amount \ of \ substance \ originally \ taken}\times 100[/tex]
On substituting the given values, we get
[tex]=\frac{0.130}{20 \ V}\times 100[/tex]
[tex]=\frac{0.65}{V} \ percent[/tex]
Note: percent = %
A nuclear power plant is scheduled to undergo a retrofitting. What is the most likely outcome of the change?
The power plant will no longer generate radioactive wastes.
The power plant will recycle the water it uses to cool the reactor.
The power plant will be able to reprocess its used uranium fuel.
The power plant will switch from fission reactions to fusion reactions.
Answer:
It's B
Explanation:
I got it right on edjenuity
The most likely outcome of the retrofitting of a nuclear power plant is that it will be able to reprocess its used uranium fuel. Therefore, option C is correct.
What is nuclear power plant?A nuclear power plant is a facility that generates electricity by harnessing the heat produced by nuclear reactions. At the heart of a nuclear power plant is the reactor, where a controlled chain reaction of nuclear fission occurs.
Reprocessing is a process by which the used nuclear fuel is chemically treated to separate out and recover the unused uranium and plutonium, which can then be reused as fuel. This reduces the amount of radioactive waste produced by the plant and also extends the life of the uranium fuel.
The fission reactions to fusion reactions is not currently a viable option for power generation, and the idea that a retrofitting would eliminate radioactive wastes is unlikely, as nuclear power plants will always produce some amount of radioactive waste.
Thus, option C is correct.
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Why is it necessary to add concentrated HCl, then water, rather than a solution of HCl to the eudiometer tube
If we add water to a concentrated acid, then the solution may boil very violently, splashing concentrated acid. If add acid to water, the solution that forms is very dilute and a small amount of heat is released.
Why do we add acid to water?When a strong acid is poured into water, it flows down the flask and mixes much better, so no boiling takes place. The addition of water to acid forms an extremely concentrated solution of acid initially. A large amount of heat is released and the solution may boil very violently, splashing concentrated acid out of the beaker and all this because the reaction is exothermic in nature.
The reason this takes place is due to a large amount of energy liberated in the hydration reaction of concentrated ions. Therefore, we add acid to water dropwise for the dilution with constant stirring and not water to acid directly.
If we add water to acid, then an exothermic reaction occurs and the solution may boil very violently. To form the dilute solution of any strong acid, you should add acid to water and the small amount of heat released is not sufficient to vaporize and spatter it.
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TRUE OR FALSE? Alloys are used more than pure metals because they are generally softer and less likely to react with air or water. WILL GIVE BRAINLIEST
Answer:
False
Explanation:
They’re used cause they’re generally harder than pure metals
Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...
So I would say false
A 12 gram piece of Cu at 475 oC is placed in contact with a 15 gram piece of Cr at 265 oC.
Assume the two pieces of metal are the system and that there is no heat exchange between system and surrounding.
What is the final temperature of the two pieces of metal expressed in degree C?
Answer:
349.22°C
Explanation:
Let the final temperature of the two pieces of metal be x.
Now, the warmer metal which is C u reduces from 475°C to x. Thus Δt for C u is; Δt1 = 475 - x.
The cooler metal Cr increases in temperature from 265°C to x. Thus, it's change in temperature is Δt for Cr is; Δt2 = x - 265.
Now from conservation of energy, the amount of energy leaving the C u metal is equal to the amount of energy entering the Cr metal.
Thus;
q_lost = q_gain
Where;
q_lost = m1•c1•Δt1
q_gained = m2•c2•Δt2
Now, c1 & c2 are the specific heat capacity of C u and Cr respectively.
From online tables, c1 = 0.385 J/g°C and c2 = 0.46 J/g°C
We are given;
m1 = 12g and m2 = 15g
Thus;
12 × 0.385 × (475 - x) = 15 × 0.46 × (x - 265)
2194.5 - 4.62x = 6.9x - 1828.5
6.9x + 4.62x = 2194.5 + 1828.5
11.52x = 4023
x = 4023/11.52
x = 349.22°C
Which one of the following is NOT a proper unit for frequency? *
m·s–1
Hz
s–1
1/s
Answer:
m*s⁻¹.
Explanation:
Hello!
In this case, since the frequency measures how repetitive an event is per unit of time, for instance the laps a car drives every 5 minutes or something similar, we can infer it has units of event/time; in such a way, the unit m*s⁻¹ is not a proper unit of frequency because it is a proper unit of velocity which is the distance traveled per unit of time.
In such a way, Hz (hertz), s⁻¹ and 1/s are possible ways frequency can be represented.
Best regards!
I need the answer multiple choice
Answer:
it's answer is
element of an atom ✌️
please help 10 points asap
Answer:
opposite
Explanation:
Answer:
opposite
Explanation:
cu9c9ucoucucpucfpufupfpucupvpjvpucu
What color do you get if you mix red and blue light?
Red and Green?
Blue and green?
What relationship do you find between frequency and energy?
What relationship do you find between wavelength and current flow?
What relationship do you find between light intensity and current flow?
Answer:
Purple light.
Yellow light.
Explanation:
The atom is one of the basic units of matter. Which part of the atom mostly determines the size of the atom?
a.Electrons
b.Nucleus
c.Neutrons
d.Protons
Answer:
Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. The separation that occurs because electrons have the same charge. The number of protons in the nucleus. The core electrons in an atom interfere with the attraction of the nucleus for the outermost electrons.
Explanation:
That would be B I believe, but please correct me if I'm wrong.
Whenever the same two elements form more than one
compound, the different masses of one element that combine
with the same mass of the other element are in the ratio of
small whole numbers.
TRUE
FALSE
Answer:
The answer is true
Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.
______ bonds form when 2 metal atoms share electrons.
Will give brainliest, Look at the graph above. Compare it to the periodic table. What do you notice about the location on the periodic table of the elements that represent the high points
Answer:
We can see that the atomic radius decreases across every row.
Explanation:
I will comment more below.
The elements that represent the highest points on the graph are all elements of group 1 and occur at the head of the period to which they belong.
The periodic table is an arrangement of elements in groups and periods. The elements in the same group have the same number of valence electrons while the elements in the same period have the same number of shells.
Looking at the graph, we can see that the high points in the graph all correspond to the group 1 elements; sodium, potassium, rubidium and cesium.The have the highest atomic radii in the period. Atomic radii increases down the group but decreases across the period. Remember that these elements are at the head of the period to which they belong hence they have the highest atomic radii.
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A commonly held idea about influenza is that it is a disease that occurs primarily in cold weather. Doctors report incidences of illness, such as influenza, to the Centers for Disease Control (CDC). The graph below shows data for three flu seasons. Note that this graph shows data from October, week 40, of one year to July, week 28, of the following year.
Which evidence supports this idea?
The graph line for 2008-09 has the highest peaks for flu.
All three graph lines show different patterns throughout the year.
The graph line for 2008-09 has a peak in week 44.
All three graph lines peak over the same few weeks of winter.
Answer:
D.All three graph lines peak over the same few weeks of winter.
Explanation:
took the test
Calculate the time required for a constant current of 0.868 A to deposit 0.387 g of Tl(III) as Tl(s) on a cathode.
Answer:
632.7 secs
Explanation:
Equation of the reaction:
Tl^3+ + 3e ------> Tl
If 1F = 96500 C
Q= It
Where;
I= current
t= time
3× 96500 C deposited 204 g of Tl
0.868 × t deposited 0.387 g of Tl
3 × 96500 × 0.387 = 204 × 0.868 × t
t= 3 × 96500 × 0.387/ 204 × 0.868
t= 632.7 secs
The time required for a constant current of 0.868 A to deposit 0.387 g of Tl(III) as Tl(s) is 2689 s
We'll begin by calculating the quantity of electricity needed to deposit 0.387 g of Ti
Ti³⁺ + 3e —> Ti
Recall:
1 mole of Ti = 48 g
1 electron (e) = 96500 C
Thus,
3 electrons = 3 × 96500 = 289500 C
From the balanced equation above,
48 g of Ti was deposited by 289500 C of electricity.
Therefore,
0.387 g of Ti will be deposited by = (0.387 × 289500) / 48 = 2334.09375 C of electricity
Finally, we shall determine the time required.Quantity of electricity (Q) = 2334.09375 C
Current (I) = 0.868 A
Time (t) =?t = Q / I
t = 2334.09375 / 0.868
t = 2689 sTherefore, the time required for the reaction is 2689 s
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Why does the flask have to be closed during the hydrochloric acid and sodium carbonate reaction?
Answer:
The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
Explanation:
The hydrochloric acid and sodium carbonate reaction was exothermic that caused the pressure to decrease. The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.
In exothermic reactions, energy is produced in the form of heat or light.
every spring has an equilibrium position which statement describe a spring at it equilibruim position?
why saturated fatty acid can’t create kink ?
HELP
What type of bond is formed between the carbon and either oxygen in CO2?
A) Single
B) Double
C) Triple
C is the element symbol for which element?
a. Carbon
b. Cadmium
c. Celenium
d. Chlorine
Answer:
A) Carbon
Explanation:
the others are wrong its A
Answer:
A) carbon
Explanation:
carbon or simply c has an atomic number of 6 and it has an atomic mass of 12.01 amu. it belongs to group 4a
which of the following is a true for subtropical jet streams
Answer: how do we answer when there are no options??
Explanation:
Please help
It’s super quick
Answer:
1. a
Explanation:
2. c
Answer:
1 is A number two is C
Which of the following statements is true regarding both theories and laws?
A: Change over time
B: Cannot be proven
C: Require consensus
D: Supported by observations
Answer:
D. Supported by observations
Explanation:
Because theories change over time, they both need to be proven, they do not go off of consensus, but they do need to be supported by observations.
HOPE IT HELPS❣️
Which of these solutions are basic at 25 °C ? A:[OH−]=2.53×10−7 M B:[H3O+]=9.99×10−9 M C:[H3O+]=6.31×10−4 M
Answer: frfg6
Explanation: 655tyyt
Which of the following elements has 3 electrons in the 2p sublevel?
O A. O
O B. C
O C. B
O DN
Answer:
the answer is D. N
AP3X
According to electronic configuration, there are 3 electrons in the 2p sublevel ,hence the correct option is D.
Electronic configuration is defined as the distribution of electrons that are present in an atom or molecule in an atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is important for understanding the structure of periodic table. It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions so as to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in their ground state and hence are said to be stable.
Thus, the correct option is D.
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A Barometer reads 29.1 inches of mercury.Calculate this pressure in mmHg.
What is the answer?
This follows a simple conversion technique. Basically what the question is trying to say here is to convert 29.1 inHg to mmHg. 1 inHg is equal to 25.4 mmHg so 29.1 inHg would be equal to [tex]25.4 * 29.1[/tex] which when evaluated turns out to be: [tex]739.14[/tex]. :D
The pressure will be 739.14 mm Hg.
What is pressure?The SI unit measuring pressure would be the pascal, which measures the force of each unit area of the surface.
Calculation of pressure
It is known that 1inHg = 25.4 mm Hg.
Hence, the pressure = 25.4 × 29.1 = 739.14 mm Hg
Therefore, the pressure will be 739.14 mm Hg.
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What mass of solute should you measure out in order to make 1,000 mL of a 0.3 M solution of magnesium phosphate Mg3(PO4)2?
Hey there !
Molecular Weight: 262.86 g/mol
Volume in liters : 1,000 mL => 1,000 / 1000 => 1 L
Number of moles of solution :
number of moles = volume x molarity
number of moles = 1 x 0.3 => 0.3 moles
Therefore:
1 mole Mg₃(PO₄)₂ ------------------- 262.86 g
0.3 moles ----------------------------- mass of Mg₃(PO₄)₂ ??
mass of Mg₃(PO₄)₂ = 0.3 x 262.86 / 1
mass of Mg(PO₄)₂ => 78.858 g
Hope this helps!