Answer:
1) It is the number of particles in one mole of substance. It is an arbitrary definition to denote an amount of substance, not by its weight but by its number of molecules. Why? because that is convenient when doing certain calculations involving molecule formulas.
2) 1 mole of substance contains exactly as many particles as there are atoms in 12 grams of carbon-12.
3) The unified atomic mass unit is 1/12 of the mass of 1 carbon-12 atom.
So you see all three concepts are linked together.
General Lab Questions: (8 points) 5. A) What is the main problem with precipitating strontium ions from the town's water using phosphate? Can you think of any reasons that your results might not be accurate?
Answer:
1) high pH is required
2) other ions are precipitated along with the strontium ions
Explanation:
According to the solubility rules all phosphates are insoluble except those of sodium, potassium, and ammonium. This implies that strontium phosphate is insoluble in water. This explains why strontium ions can be precipitated from drinking water supply using phosphate. The main problem with the precipitation of strontium using phosphate is that it usually requires a high pH as the precipitation occurs under very alkaline conditions.
The main reason why the results may not be accurate is that other ions are precipitated along with the strontium such as calcium ions and magnesium ions. This may lead to inaccurate determination of the amount of strontium ions present.
Answer:
Explanation:
The fundamental issue for precipitation of Strontium Phosphate, is that the other metal cations (Calcium, Barium, Iron, and so on.), present in the town water, are likewise encouraged as Phosphate. In this manner, alongside Strontium Phosphate, Phosphates of a few different cations are additionally encouraged. In this way, Strontium Phosphate can't be weighed precisely. This will prompt off base outcomes.
The response will be Exothermic, if the temperature of response increments.
an element x atomic number 16 reacts with an element Y atomic number 20 to form a compound
i) position of the elements in the modern periodic table
ii) what type of bond will be formed between them ? give reason
iii) write the chemical formula of the compound
Answer:
Element x has an atomic number of 16, it is sulphur.
Element Y has an atomic number of 20, it is calcium.
i) Sulphur is in Group VI, period 3 in the modern periodic table,
whereas calcium is in Group II, period 4 of the modern periodic table.
ii) Ionic bonds will form between them. This is because metals and non-metals (Cacium and sulphur) usually form ionic compounds where between the ions are held by ionic bonds (which are transferred electrons so that both elements can attain a stable status).
iii) CaS
each Calcium atom can lose 2 electrons to attain 8 outermost shell electrons, while each sulphur atom can gain the 2 electrons to attain 8 outermost shell electrons, where they will most be stable (octet). Hence, the atomic ratio of Ca and S is 1:1.
i) The element with atomic number 16 is sulfur present in group 16 and period 3rd and the element with atomic number 20 is calcium present in group 2 and period 4th.
ii) The ionic bond formed between them.
ii) The chemical formula of the compound will be CaS.
What are ionic compounds?Ionic compounds can be described as crystalline solids formed by closely packed ions of opposite charge. An Ionic compound is generally formed when metal reacts with non-metal.
In ionic compounds, the ions are commonly held together by ionic bonds. The ions are formed by gaining or losing electrons in order to achieve their nearest noble gas configuration.
In a reaction, the metals usually lose electrons to complete their octet while non-metals will gain electrons to complete their octet.
The given element calcium is a metal with a valency of +2 and sulfur is a non metal with a valency of -2. Therefore, they form an ionic compound with the chemical formula CaS.
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Name each of the following binary compounds or ionic compounds with polyatomic ions: 1. LiBr 2. Cal2 3. Al203 4. Mg3N2 5. FeCl2 6. FeCl3 7. Cu3N2 8. Ni2O3 9. Al(SO4)3 10. Ca3(PO4)2 11. Fe(OH)2 12. (NH4)2S 13. Na2O 14. NH3 15. SO42-
Answer:
Explanation:
1. LiBr - Lithium bromide
2. Cal₂ - Calcium iodide
3. Al₂0₃ - Aluminium oxide
4. Mg₃N₂ - Magnesium nitride
5. FeCl₂ Ferrous chloride [ Iron(II) chloride ]
6. FeCl₃ Ferric chloride [ Iron(III) chloride ]
7. Cu₃N₂ Copper nitride
8. Ni₂O₃ Nickel(III) oxide
9. Al(SO4)₃ Aluminium sulphate
10. Ca₃(PO4)₂ Copper phosphate
11. Fe(OH)₂ Iron (II) hydroxide
12. (NH4)₂S Ammonium sulphide
13. Na₂O Sodium oxide
14. NH₃ Ammonia
15. SO₄²⁻ Sulphate ion
Production of synthetic fibers helps in the conservation of forests comment
Answer:
Explanation:
Synthetic fibres are made using chemicals. Hence they do not require any forest resources like wood. This helps in saving the trees from cutting down. So the production of synthetic fibers helps in the conservation of forests.
Natural fibres on the other hand require forest products like wood for its manufacture.
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Answer:
yes, they do help in conservating the forest resources.
Explanation: This is because synthetic fibers like rayon, nylon etc are made from petrochemicals which helps to substitute usage of natural resources like cotton etc. and these synthetic fibers are more durable than natural fibers, which adds to their usage and in turn, helps to conserve forest resources.
1 Cup of Boiling Water
WAPHS Swimming Pool
(100 °C)
or
(25 °C)
• What is the difference between thermal energy and
temperature?
aterials
Enosh
Odates
ades
stery
endance
mbers
• The boiling water has a much higher temperature... What
does that mean?
nferences
enuity Ele
enuity se
sela
• Which has more thermal energy? Why?
Note Cla
Learnir
9
1 Mop
Answer:
Side photo
A small still is separating propane and butane at 135 °C, and initially contains 10 kg moles of a mixture whose composition is x = 0.3 (x = mole fraction butane). Additional mixture (x = 0.3) is fed at the rate of 5 kg mole/hr. The total volume of the liquid in the still is constant, and the concentration of the vapor from the still (xp) is related to x, as follows: Xp = How long will it take for X, to change from 0.3 to 0.35.
Answer: A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C. However, the swimming pool contains a lot more water. Therefore, the pool has more thermal energy than the cup of tea even though the tea is hotter than the water in the pool.
Explanation: Heat and Temperature do not mean the same thing. ... A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C. However, the swimming pool contains a lot more water. Therefore, the pool has more thermal energy than the cup of tea even though the tea is hotter than the water in the pool.
When a gas is put in a container it...
a. does not change shape.
b. fills up the container.
c. fills up the container and fills it up top to bottom.
Answer:
c.is the answer..not sure...but i think so
The production of water proceeds according to the following equation.
2H2(g) + O2(g) → 2H2O(g)
Which describes a way to speed up the collisions between hydrogen and oxygen molecule:
Use a less-intense source of heat on the reactants.
Maintain the same temperature of the reactants.
Place the reactants in a smaller container.
Reduce the concentration of the reactants.
Answer:
Place the reactants in a smaller container.
Explanation:
If you were to reduce the source of heat, the hydrogen and oxygen molecules would lose their kinetic energy, resulting in less collisions.
_______________________________________________________
Maintaining the same temperature of the reactants, the speed would neither increase nor decrease as temperature is directly proportional to the kinetic energy of the molecules, which in turn is directly proportional to the number of collisions. However, placing the reactants in a smaller container would result in less volume, and hence the molecules would collide with one another more often!
Hope that helps!
The primary requirement of a reaction to occur is that the reactant particles must collide and interact with each other in some way. Place the reactants in a smaller container which speed up the collisions between hydrogen and oxygen molecule. The correct option is C.
What is collision theory?The collision theory states that the rate of a chemical reaction is proportional to the number of collisions between the reactant molecules. The more often reactant molecules collide, the more often they react with one another and faster will be the reaction rate.
If we reduce the source of heat, the hydrogen and oxygen molecules would lose their kinetic energy, resulting in less collisions. The temperature is directly proportional to the kinetic energy of the molecules, which in turn is directly proportional to the number of collisions.
If we place the reactants in a smaller container it would result in less volume, and hence the molecules would collide with one another more often.
Thus the correct option is C.
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What type of compound are carbon tetrachloride and boron trihydride?
Answer:
hydrocarbon
Explanation:
these are called hydrocarbons
What is the percent yield of ferrous sulfide if the actual yield is 220.0 g and the theoretical yield is 275.6 g? Use Percent yield equals StartFraction actual yield over theoretical yield EndFraction times 100.. 12.5% 55.6% 79.8% 87.9%
Answer:
79.8%
Explanation:
Percentage yield = actual yield / theoretical yield x 100%
Percentage yield = 220.0 / 275.6 x 100%
=79.8%
The percent yield of of ferrous sulfide if the actual yield is 220.0 g and the theoretical yield is 275.6 g is 79.8%.
What is percent yield?Percent yield is defined as the ratio of actual yield to the theoretical yield multiplied by 100. If the actual and theoretical yield are same then the percent yield is 100%.If actual yield is less than the theoretical yield then the percent yield is less than 100%.Reason of this condition arising is the incompletion of reaction or loss of sample during recovery process.
In cases where percent yield is over 100% it indicates that more sample is recovered than the predicted amount.This condition arises when there are other simultaneous reactions taking place leading to the formation of product. It can also arise if there is incomplete removal of impurities from the sample .
In the given example, percent yield can be found out by substituting values in mentioned formula. percent yield,=220/275.6×100=79.8%.
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What can you infer about the results of numerical models in 1966 for polar caps
made of water ice?
Answer:
that by living near the poles, people might be able to survive on Mars
Explanation:
HELP PLEASEE 100 POINTS
The Quiver tree grows in Southern Africa. Which of the following plant adaptations is likely to prevent these trees from dying out due to rising desert temperatures?
O Releasing a black powder onto their trunk to absorb more heat from sunlight
O Shifting their growing range towards the equator
Ability to store water in leafy structures to prevent excess evaporation
O Limiting seed dispersal to nearby locations
PLEASE HELP 100 POINTS !!
Answer:
Shifting their growing range towards the equator
Explanation:
Maybe will be like that
Answer:
Ability to store water in leafy structures to prevent excess evaporation.
Explanation:
The reason why plants die in hot temperature is the excess evaporation of water, so to prevent the excess evaporation of water, the plants get adaptive to store water in their leaves.
Hope it helps.
PLEASE HELP RIGHT AWAY!! THANK YOU :)
Copper turns a green-brown when it is exposed to oxygen in air. What chemical property of oxygen causes this effect?
A). its reactivity
B). its mass
C). its flammability
D). its volume
Answer:
The answer is option A.
its reactivity
I hope this helps you.
Answer:
A) Reactivity
Explanation:
Reactivity is one of the characteristics of a chemical property. The copper that turned color due to air, has a different chemical composition.
It wouldn't be flammability - even though it is a chemical property, but nothing is burning.
All the other answer choises: mass and volume are physical properties. Basically the PHYSICAL characteristics which doesn't change the composition.
Hope this helps!
What would be the mass of Iron(II) chloride obtained when 450g of Sodium Chloride is added to Iron(II) oxide?
Answer:
FeO(s)+2NaCL(aq)>FeCL2(aq)+Na2O(s)
2 moles of sodium chloride react with 1 mole of iron (II) oxide to give 1 mole of iron (II) chlorine
mole ratio NaCl :FeCl=2:1
mass of FeCl=0.5×450=225g
Explanation:
(
What is cationic and anionic polymers?
Answer:
Explanation:
Anionic polymerization and cationic polymerization are two types of chain growth polymerization reactions which are used to synthesize various types of polymers. Both these reactions have the same reaction mechanism, but the reaction initiator is different. Anionic polymerization reactions are initiated by an active anionic species, whereas the cationic polymerization reactions are initiated by an active cationic species.
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What marine province contains deep ocean trenches that form along convergent plate boundaries as a result of subduction?
A. Mid-ocean ridge
B. Deep ocean basin
C. Abyssal plain
. Continental margin
Answer:
A.Mid ocean ridge i think
Explanation:
your answer is B my guy
¿A qué grupo pertenecen los átomos de Z = 8, Z= 36 y Z=39? ¿Cuántas capas de electrones tiene cada uno? ¿Cuántos electrones harían falta para llenar la capa más externa?
Answer:
Mira la explicación.
Explanation:
¡Hola!
En este caso, podemos encontrar facilmente el grupo al que pertenecen dichos elementos con números atómicos 8, 36 y 39 respectivamente mediante su búsqueda en la tabla periódica. Así, z=8 corresponde a oxígeno, z=36 a kriptón y z=39 a itrio.
Por otro lado, para saber el número de capas, debemos desarrollar la configuración electrónica para cada uno:
[tex]O: 1s^2,2s^2,2p^4\\Kr: 1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^{10},4p^6\\Y:1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^{10},4p^6,5s^2,4d^1[/tex]
Con esto, vemos que oxígeno tiene dos capas, kripton cuatro capas e iritrio cinco, a lo que a oxígeno le faltan dos electrones para llenar dicha capa, a kripton ninguno y a iritrio nueve.
Saludos.
You are on an island and need freshwater to drink. Which process could you
use to separate the salt from ocean water and provide freshwater for
drinking?
O A. Distillation
B. Chromatography
C. Filtering
O D. Freezing
Answer:
A
Explanation:
The reason it is distillation is due to the fact that we can use distillation to heat the ocean water. As water has a lower boiling point than the salt solution, it evaporates and the salt stays behind.
What was the plum-pudding atomic model? A. A description of atoms being balls of positive charge with electrons scattered outside B. A description of electrons orbiting the nucleus of the atom C. A description of electrons scattered inside the atom D. A description of negative charges being suspended between balls of positive charge
Answer:
C
Explanation:
plum- pudding atomic model is an atom that had a positively charged medium, or space, with negatively charged electrons inside the medium.
The correct answer is (A) A description of atoms being balls of positive charge with electrons scattered outside.
What is plum pudding atomic model? The plum pudding atomic model was proposed by JJ Thomson.This atomic model had electrons embedded with positive charge.The plums were negatively charged electrons the pudding were the positively-charged protons. Why other options are incorrect?
Option (A) is correct because the atom was a sphere of positive charge with negatively charged electrons scattered around the atom like plums in a pudding.
So , Rest options that are B , C and D are incorrect.
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ON A TIMER!!! PLZ HELP ME!!!
Consider the reaction below. *Image* Which is the net ionic equation for the reaction?
Answer:
C2H3O2^-(aq) + H^+ —> HC2H3O2
Explanation:
The following equation was given in the question:
Na^+ + C2H3O2^-(aq) + H^+ Cl^- —> Na^+ + Cl^- + HC2H3O2
Now, to obtain the net ionic equation, we simply cancel out the ions common to both side of the equation.
A careful observation of the equation above, shows that sodium ion, Na^+ and chloride ion, Cl^- are common to both side of the equation.
Therefore, to obtain the net ionic equation, we simply cancel out Na^+ and Cl^- from both side of the equation. This is illustrated below:
Na^+ + C2H3O2^-(aq) + H^+ Cl^- —> Na^+ + Cl^- + HC2H3O2
C2H3O2^-(aq) + H^+ —> HC2H3O2
Therefore, the net ionic equation is
C2H3O2^-(aq) + H^+ —> HC2H3O2
why does bromine not react with sulphur?
Answer:
The thermodynamic parameter which is of significance in this case is the 'Reduction Potential' for molecular bromine which is ~ +1.1 v vs N.H.E. In other words, it is a strong oxidizing agent. The bromine will oxidize sulfur compounds in which the valence of sulfur is lower than six to sulfate.
There are many possible reactions. Here is one possible example:
Na2 S2O3 + 4Br2 + 5 H2O = 2NaHSO4 + 8 HBr
Answer:
because bromine doesn't have a reaction channel on Yootube.
Explanation:
Speaks for itself.
C AL= -4.184 × 39.85 × 4.7 ÷ 11.98 × (-72.9)
Answer:
4,768.57
Explanation:
If you are asking us to calculate, your answer is above. Easiest and fastest way is to plug it into the calc.
HURRY I'M ON A TIMER
A stovetop bumer on medium reaches 95°C. Which other object will receive a flow of heat directly from the burner?
the surrounding air
a burner at the same temperature
a pan heated to 100°C
hotter water inside a pan
Answer:the surrounding air
Explanation:
A burner at the sanem temperature would not receive a flow of heat, a pan heated to 100 degrees will transfer heat to the stovetop, and hotter water inside a pan will not take the heat either because it is hotter. the surrounding air is colder and will take heat from the burner
Answer:
surrounding air
Explanation:
taking test too
how many atoms altogether make up one molecule of glucose
Answer:
24 atoms makes altogether a molecule of glucose
A group of students conducts an experiment to test the amount of sugar that can be dissolved in water at 50°F, 100°F, and 200°F.
Which suggestion will help increase confidence in the result?
A. Michael suggests timing each addition of sugar
B. Ali suggests using her hand to verify the temperature of the water
C. Joel suggests testing salt along with sugar to see if they dissolve at different speeds
D. Zander suggests that each student complete an experiment individually and compare results
Answer:
A. Michael suggests timing each addition of sugar
Explanation:
The experiment is about amount of sugar dissolved at different temperatures. The suggestion of Michael is best suited to record the timing of each addition of sugar. This will enable to record the timing of sugar added in the water and amount of sugar dissolved at the specified temperature.
A metal strip reacts slowly when placed in a light blue solution, and much faster when placed in a dark blue solution at the same temperature. Using the collision theory, explain this phenomenon.
Answer:
Increase in the color intensity and hence the concentration of the reacting species increases the rate of the reaction according to collision theory
Explanation:
The given parameters are;
Rate of reaction of metal strip in light blue solution lesser than rate of reaction of the metal strip in dark blue solution
Therefore, the color of the solution derives from the concentration of the reacting species involved in the reaction.
The increase in the darkness of the blue solution stems from the increase in the concentration of the reacting species which according to collision theory increases the fraction of the effective collisions, thereby increasing the reaction rate.
Which produces oxygen-18 when it undergoes beta decay? A. oxygen-17 B. oxygen-18 C. fluorine-17 D. fluorine-18
Answer:
Option D. fluorine-18
Explanation:
The attached photo gives the explanation.
In the attached photo, A zX represent the atom that will undergo beta decay to produce oxygen–18.
After the calculation, A zX was found to be fluorine–18.
Boiling point of water at 750 mmHg is 99.63⁰C. How much sucrose is to be added to 500 g of water such that it boils at 100⁰C. Kb for water 0.52 K Kg mol-1
Answer:
121.67 g is to be added to 500 g of water
Explanation:
Given that:
Pressure = 750 mmHg
Temperature T₁= 99.63⁰C = (273 + 99.63 ) = 372.63K
mass of water = 500 g
Temperature T₂ = 100⁰C = ( 273 + 100) K = 373 K
where;
Kb for water 0.52 K Kg mol-1
For sucrose; C₁₂ H₂₂ O₁₁
Molar mass = ( 12 × 12 )+ ( 1 × 22 ) + ( 16 × 11 )
Molar mass = 342 g/mol
ΔT = T₂ - T₁
ΔT = (373 - 372.63)K
ΔT = 0.37 K
∴ the amount of sucrose to be added to 500 g of water is:
[tex]= \dfrac{0.37\times 342 \times 500}{0.52 \times 1000 }[/tex]
[tex]= \dfrac{6327}{52}[/tex]
= 121.67 g
Thus; 121.67 g is to be added to 500 g of water
How many grams of AuCl2, if the compound has 6.3 x10^23 atoms of Cl?
Answer:
Total mass = 93.21 gram (Approx)
Step-by-step explanation:
Given:
Atoms of Cl = 6.3 × 10²³
Find:
Amount of AuCl₂
Computation:
Molecules of AuCl₂ = 6.3 × 10²³ / 2 = 3.15 × 10²³
1 mol of AuCl₂ = 6.022 × 10²³ molecules
Number of mol = 3.15 × 10²³ / 6.022 × 10²³
Number of mol = 0.523 mol
So,
Molar mass of AuCl₂ = 267.87 g/mol
Total mass = 0.348 mol × 267.87 g/mol
Total mass = 93.21 gram (Approx)
how many moles of water (H2O) would be produced from the reaction of 3.25 moles of hydrochloric acid (HCL) reacting with excess calcium hydroxide (Ca(OH)2)
Answer:
3.25 moles of H2O
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2HCl + Ca(OH)2 —> CaCl2 +2H2O
Now, we can obtain the number of mole H2O produced from the reaction as follow:
From the balanced equation above,
2 moles of HCl reacted to produce 2 moles of H2O.
Therefore, 3.25 moles of HCl will also react to produce 3.25 moles of H2O.
Therefore, 3.25 moles of H2O were produced from the reaction.
Dr. Tate and Dr. Ramirez are observing the effects of a type of solar activity that has reached the planet Jupiter. What solar activity are they observing? a.solar flares b.sunspots c.prominences d. solar winds
Answer:
d. solar winds
Explanation:
Dr. Tate and Dr. Ramirez are observing solar winds coming from the sun. Solar winds occurs naturally in which the particles such as electrons and photons releases from the surface of the sun into the space. These solar winds moves in the solar system and interact with planets of the solar system. Dr. Tate and Dr. Ramirez are the two well known scientist observing the effects of solar winds that has reached the planet Jupiter.