Answer:
Explanation:
1. Cornstarch and water - decantation
2. Iron and sulfur
3. Rice grains and stones - sieving
4. Pebbles and soil - decantation
5. Muddy water - decantation
6. Ground pepper and water - decantation
7. Flour and coarsely ground corn - sieving
8. Needles in a box of beads - using a magnet
9. Sesame seeds in soy sauce -
10. Pebbles and iron nails - using a magnet
11. Fine sand from rocks - sieving
12. Sand from water - filtration
13. Gravel and sand - sieving
14. Salt and iron filings - sieving
15. Pins from assorted buttons - using a magnet
16. Coconut oil from coconut milk - filtration
17. Sand and pebbles - sieving
18. Pasta from water - sieving
19. Sand and thumb tacks - using a magnet
20. Salt solution - filtration
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 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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why saturated fatty acid can’t create kink ?
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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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!
Answer them please thanks
Answer:
(3) sorry if I'm wrong
7. (1-fertilization [sorry if wrong again]
8. (4-mitosis
Explanation:
I'm learning about this right now...Sorry if I'm wrong but I'm pretty sure they're right! Hope this helps tho! if I'm right maybe mark me brainliest?
PLEASE HELP ME!!!!!!!!!!!!!!!!!!!
WRITE A SHORT PASSAGE ON HOW FIBRES ARE SPUN
HELPPP WILL MARK AS BRAINLIEST
Answer: Spun yarn is made by twisting staple fibers together
To make a cohesive thread Or “single”. Twisting fibers, into yarn in the process called spinning can be dated back to the upper Paleolithic. Yarn spinning was one of the first processes to be industrialized.
Explanation:
An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.
Answer: The percent yield of the reaction is 77.0 %
Explanation:
[tex]2Pb+O_2\rightarrow 2PbO[/tex]
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]
[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]
According to stoichiometry:
2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]
2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]
Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]
percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]
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.
Draw and name the structures of the carboxylic acids and esters you put together using molecular models.
Answer:
This question is incomplete
Explanation:
However, when the carboxylic acids and esters put together are obtained, the procedure below can be followed in drawing and naming them.
For carboxylic acid,
1) it should be noted that the functional group here is -COOH which is drawn as -C = OH
|
OH
2) The carbon of the functional group is included among the carbon to be counted when naming the structure. For example, the compound below is propanoic acid.
CH₃CH₂COOH - As you can see that there are 3 carbons linked chain there.
3) As can be seen in (2) above, the suffix "oic" is used to name carboxylic acids
4) The carbon chain here is saturated (meaning there is no double or triple bond within the carbon chain)
Example of a structure of carboxylic acid is
H₃C - CH₂ - CH₂ - C = OH
|
OH
The structure above is a butanoic acid
For ester
1)The functional group here is -COO- . which can be drawn as
- C = O
|
O -
(meaning one oxygen atom is double bonded to the carbon and the other oxygen atom is bonded to another carbon chain)
2) The alkyl group attached to the oxygen atom is first of all mentioned before the carbon chain attached from the left is mentioned. For example, CH₃CH₂CH₂COOCH₂CH₃ is ethyl butanoate
3) As seen from (2) above, the suffix "oate" is used to end the name of esters
4) As also seen from (2) above, the carbon of the functional group is also included while counting the carbon chain of the parent name (butanoate).
5) The carbon chains here are also saturated.
Example of this ester is
CH₃CH₂C = O
|
O - CH₂CH₃
The name of this compound is ethyl propanoate
An atom has 8 protons, 8 neutrons and 9 electrons. is thus a cation, anion, or neutral atom?
Answer:
It is an Anion because there are more electrons than protons making it negative
______ bonds form when 2 metal atoms share electrons.
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.
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 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.
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
please help 10 points asap
Answer:
opposite
Explanation:
Answer:
opposite
Explanation:
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What is one example of chemical weathering affecting a rock
Answer:
one example of chemical weathering is when carbon dioxide mixes with water.
Explanation:
when dioxide mixes with water it creates carbonation.
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❣️
I need the answer multiple choice
Answer:
it's answer is
element of an atom ✌️
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
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
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
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
The reaction of zinc metal and hydrochloric acid produces hydrogen gas and zinc chloride. Write the balanced chemical equation. Phases are optional.
Answer:
Zn + 2HCl -----> ZnCl₂ + H₂
Explanation:
The balanced chemical equation for Zn with hydrogen is Zn + 2HCl ---> ZnCl₂+ H₂.
What is balanced chemical equation?
A balanced chemical equation is one in which number of reactant is equal to number of products. When Zinc reacts with hydrogen it will form zinc chloride and hydrogen gas.
Here, 1 molecules of hydrochloric acid are participating in the process, and 1 molecules of hydrogen are being created.
Therefore, The balanced chemical equation for Zn with hydrogen is Zn + 2HCl ---> ZnCl₂+ H₂.
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Which of the following macromolecule is the main energy source for most living organisms?
A. Nucleic Acids
B. Carbohydrates
C. Lipids
D. Proteins
Answer:
Carbohydrates
Explanation:
Living things use carbohydrates as their main source of energy. The breakdown of sugars, such as glucose, supplies immediate energy for cell activities. Plants, some animals, and other organisms also use carbohydrates for structural purposes.
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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17. Which is a fat-soluble vitamin?
O vitamin B
O vitamin C
O vitamin A
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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