Answer:
(a) Total impurities = 17.5%
(b)
(i) 5 tons of ore yields 2185 kg of aluminium
(ii) 5 tons of ore contains 375 kg of sand
(c) Percentage of Al2O3 in purified ore = 825/900 = 91.7%
Explanation:
Q7. Aluminum is extracted from the ore bauxite, which is impure aluminum oxide.
1 tonne (1000 kg) of the ore was found to have this composition:
1. aluminum oxide 825 kg (82.5%)
2.iron(III) oxide 100 kg (10%)
3.sand 75 kg (7.5%)
(a) Since we are interested only in extracted aluminium, everything other than aluminium oxide is considered impurity, which includes Fe2O3 (10%) and sand (7.5%). Total impurities = 10+7.5 = 17.5%
(b) "1 tonne of the ore gives 437 kg of aluminum."
(i) 1 ton of ore : 437 kg Al = 5 tons of ore : x kg of Al
Cross multiply
x = 5 tons * 437 kg / 1 ton = 2185 kg of aluminium
(ii) 1 ton of ore contains 75 kg of sand
5 tons of or contains x kg
x = 5*75/1 = 375 kg of sand
(c) If the ore is purified from Fe2O3, then for each ton of ore, there will be left
825 kg of aluminium oxide,
75 kg of sand
for a total of 900 kg.
Percentage of Al2O3 = 825/900 = 91.7%
Answer:
A) 17.5 %
B) 1) 2135 kg
2) 375 kg
C) 91.8%
Explanation:
Part (A):
1 tonne = 1000 kg = 100%
Aluminium oxide = 825 kg = 82.5%
Iron (III) oxide = 100 kg = 10%
Sand = 75 kg = 7.5%
That makes total of 100%
So, the percentage of impurities = Iron (III) oxide + Sand
=> 10 + 7.5 = 17.5%
Part (B):
(1) 1 tonne = 427 kg
Multiplying both sides by 5
=> 5 tonne = 427 * 5
=> 5 tonnes = 2135 kg
(2) 1 tonne contains 75 kg sand as impurity
=> 1 tonne = 75 kg
Multiplying both sides by 5
=> 5 tonnes = 75*5
=> 5 tonnes = 375 kg
Part (C):
If all of the iron oxide was removed, then only aluminium and sand are left.
Aluminium = 825 kg
Sand = 74 kg
Total of them makes it:
=> 825 + 74 = 899
So,
%age of Aluminium = [tex]\frac{825}{899} * 100[/tex]
%age of Aluminium = 0.918 * 100%
%age of Aluminium = 91.8%
If he wants to model a longitudinal wave that carries more energy, how should he move the end of the spring?
Answer:
they won
Explanation:
Matter is composed of exceedingly small particles called atoms. An atom is the
smallest unit of an element that can participate in a -------
Answer:
Matter is composed of exceedingly small particles called atoms. An atom is the
smallest unit of an element that can participate in a chemical reaction.
Answer:
Chemical reaction.
Explanation:
what particle determines the name of the element?
Answer:
The protons determine the name of an element and also atomic number because its the same as protons.
What letter represents the enthalpy of reaction?
Answer:
Option D. T
Explanation:
Enthalpy change (ΔH) is simply the difference between the heat content of the product (Hp) and the heat content of the reactant (Hr). Mathematically, it is expressed as:
Enthalpy change (ΔH) = Heat of product (Hp) – heat of reactant (Hr)
ΔH = Hp – Hr
From the diagram given above, the difference between the heat content of product and the heat content of reactant is T.
Therefore, the enthalpy change of the reaction is T.
The volume of a sample of pure HCl gas was 221 mL at 20°C and 111 mmHg. It was completely dissolved in about 50 mL of water and titrated with an NaOH solution; 18.7 mL of the NaOH solution was required to neutralize the HCl. Calculate the molarity of the NaOH solution.
Answer:
[tex]molarity =6.9\times 10^{-3}\ M\\[/tex]
Explanation:
We know that , the reaction of HCl and NaOH is given as follows
[tex]NaOH+HCl=NaCl +H_2O[/tex]
Given that
Pressure = 111 mm Hg
[tex]P=111\times 13.6\times 10^{-3}\times 9.81\times 1000=14.809\ kPa[/tex]
Temperature = 20°C
T=20+273=293 K
Volume= 221 m L
V=0.221 L
Number of moles of HCl is given as follows
[tex]n=\dfrac{P\times V}{R\times T}\\n=\dfrac{0.148\times 0.221}{0.821\times 293}=1.3\times 10^{-4}\ moles[/tex]
From the above reaction we can say that
Number of moles of HCl=Number of moles of NaOH
Volume of NaoH is given as follows
V=18.7 = 0.0187 L
Therefore molarity
[tex]molarity =\dfrac{n}{V_{NaOH}}\\molarity =\dfrac{1.3\times 10^{-4}}{0.0187}=6.9\times 10^{-3}\ M\\molarity =6.9\times 10^{-3}\ M\\[/tex]
A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained with pH at equivalence point of around 8. The unknown compound is ________.
Answer:
Weak acid
Explanation:
A titration curve is a graphical description of the change in pH of the solution in the conical flask as the reagent is added from the burette. A titration curve can be plotted for the different kinds of acid and base titrations. The volume of the titrant is always plotted as the independent variable and the pH of the solution as the dependent variable. The equivalence point is read off from the titration curve. A titration curve is very important because it shows the pH at various points during the titration.
A weak acid/strong base titration leads to an equivalence point above 7. From the question, we were told that the pH at equivalence point lies around 8. Hence the unknown substance must be a weak acid.
show bond formation in magnesium chloride
mg has a 2 in its valence shell
it will become mgcl2
. . . .
: Cl -------- Mg ------ Cl :
. . . .
Period, group and atomic number of the elements that have the following electrical configurations: 1s2 2s2 2p3 1s2 2s2 2p6 3s2 1s2 2s2 2p5
Answer:
If you follow the periodic table and its orbitals, you'll see that the element that has the electron configuration of 1s²2s²2p³ is Nitrogen. It's period, group, and atomic number are 2, 15, and 7 respectively. The other 2 are Neon, who's period, group, and atomic number are 2, 18, and 10 and the last one is Fluorine, who's period, group, and atomic number are 2, 17, and 9.
Which best describes a neutralization
reaction?
A) a reaction between an acid and a base
B) a reaction between two acids
C) a reaction between a base and a salt
D) a reaction between two salts
Explanation:
The Answer is a reaction between two acids
144g of KCl dissolved in 1000cm3of water at 90oC. Calculate the solubility of KCl at this temperature. (K=39, Cl=35.5, 1dm3=1000cm3).
Answer:
The solubility of KCl is 1.93 mol/dm³
Explanation:
The information given are;
The mass of the potassium chloride, KCl = 144 g
The volume of the water solvent = 1000 cm³ = 1 dm³
The temperature of the solvent = 90 °C
The atomic mass of potassium, K = 39 u
The atomic mass of chlorine, Cl = 35.5 u
The number of moles of potassium in one mole of potassium chloride, KCl = 1 mole
The number of moles of chlorine in one mole of potassium chloride, KCl = 1 mole
The molar mass of the potassium chloride = 39 + 35.5 = 74.5 g/mol
The number of moles, n, of potassium chloride, KCl in 144 g of potassium chloride, KCl is given as follows
n = Mass/(Molar mass) = 144/74.5 = 1.93 moles
1.93 moles will dissolve in 1 dm³
Therefore, the solubility of KCl is 1.93 mol/dm³.
What's the valency of sulphur for SO2?
Answer:
The valency of sulphur in SO2 is 4.
Hope this helps..
[tex]good \: luck[/tex]
Na-23 has 12 neutrons. What is it’s atomic number?
Answer:
11
Explanation:
Data obtained from the question include:
Mass number = 23
Neutron = 12
Atomic number =.?
Next, we shall determine the number of protons present in the element.
This can be achieved by doing the following:
Mass number = Proton + Neutron
Mass number = 23
Neutron = 12
Proton =...?
Mass number = Proton + Neutron
23 = Proton + 12
Collect like terms
Proton = 23 – 12
Proton = 11
The atomic number of an element is equal to the proton number.
Atomic number = proton number
Proton number = 11
Atomic number = proton = 11
Therefore, the atomic number is 11.
Which property would cesium most likely have?
Answer: The property that cesium most likely would have is being ductile (able to be deformed without losing toughness) due it being a very soft, alkali metal which has a very low melting point of 83.3 °F or 28.5 °C
Answer:
The answer is B. Ductile.
Explanation: Cesium belongs to a category of metals. They are often silver, fairly soft, and very ductile. The answer is right on edge 2020.
List at least four characteristics of acids
Answer:
pH>7
sour taste
donate H+ ions
turn litmus paper from blue to red
Explanation:
Answer:
Explanation:
pH < 7.
Sour taste (though you should never use this characteristic to identify an acid in the lab)
Reacts with a metal to form hydrogen gas.
Increases the H+ concentration in water.
Donates H+ ions.
Turns blue litmus indicator red.
What is the concentration of a solution if 65 g of sugar is dissolved into 200 ml of water?
Answer: the concentration in g/L 325 while in molarity is 0.6398(M).
Answer:
325 g/L,
0.9503 M
Explanation:
65 g sugar --- 0.2 L
x g --- 1 L
x = 65/0.2 g/L = 325 g/L
Sugar(sucrose) is C12H22O11.
Molar mass (C12H22O11) = 12*12 + 1*22 + 16*11 = 342 g/mol
325 g/L * 1 mol/342 g = 0.9503 mol/L = 0.9503 M
Answer 0.6398(M) is not related to sugar (sucrose),
it should be given formula or molar mass of sugar if it is different than sucrose.
25. Which answer best describes the continental rise? area of land that drops toward deep ocean basins 75 mile shallow flat area just off coastlines thick deposits of sediments carried off of the shelf the surf area along coastlines
Answer:
Thick deposits of sediments carried off of the shelf
Explanation:
The continental rise is a thick deposit of sediments that accumulate between the continental slope and the abyssal plain
A is wrong. The area of land that drops toward the deep ocean basins is the continental slope.
B is wrong. The 75-mile shallow flat area just off coastlines is the continental shelf.
D is wrong. The surf area along coastlines is the surf zone .
Why do group 12 elements have different properties than group 13 elements
Answer:
A
Explanation:
in terms of bonds, what would the molecule C3H6 be classified as
Explanation:
Cyclopropane is a cycloalkane conposed of three carbon atoms to form a ring. It has a rols as an inhalation anaesthetic. It is a cycloalkane and a member of cyclopropanes.
Answer:
Alkane
Explanation:
1) Determine a fórmula da base hidróxido de bário: * 1 ponto a) b) c) d) 2) As bases são substâncias iônicas, ou seja, quando são solubilizadas em água liberam íons, qual das características abaixo pode ser atribuída as soluções iônicas? * 1 ponto a) Conduzem corrente elétrica. B) Isolantes elétricos. C) Radioatividade. D) Emissão de raio UVA.
Answer:
1) Ba(OH)₂
2) The correct option is a) they conduct electricity.
Explanation:
To deduce the formula of Barium hydroxide, we have to go to the periodic table and look for the Barium (Ba), which is in group 2 and has an ionic charge of 2+. Hydroxides are not an element that is present in the periodic table is the combination of Oxygen and Hydrogen (OH), and its ionic charge is 1-.
To name this substance, we write the elements that form it, which are Ba OH, then we see the ionic charges that they have, Ba2+ OH 1- and we change these charges giving the 2+ to the OH and the 1- to the Ba. It would look Ba OH₂; we do not write the 1, and as there is a 2, the OH, has to be between brackets so that the final formula is Ba(OH)₂. What we did is balancing the charges of the elements. In other words, we need 2 OH for every Ba. Hydroxides give an electron to balance the Ba ionic charge.
Barium Hydroxide is an ionic compound because ionic compounds are formed by a metal (Ba) and a nonmetal element (OH), ionic compounds are charged, so when they are in an aqueous solution they conduct electricity because their ions move freely in the solution.
Adrian loves the pancakes! The problem is, the recipe serves only six, and he has 540 people in his family (including aunts, uncles, and cousins). Now, he needs help increasing the recipe to feed his entire family. However, Adrian is particular - he insists on using only three significant figures with scientific notation.
Answer:
ingredient. U.s unit. SI unit. SI unit(540)
flour. 2cups. ²/6. 180cups = 1.8×10²
milk. 2cups. ²/6. 180cups. =1.8×10²
eggs. 2. ²/6. 180eggs. =1.8×10²
melted butter. ⅓cup ¹/18. 30cups. =3×10¹
sugar. 1spoon. ¹/6. 90spoons. =9×10¹
baking powder 2spoons ²/6. 180spoons. =1.8×10²
salt. ½spoon. ¹/12. 45spoons. =4.5×10¹
Explanation:
1) to get the SI unit divide the U.S unit by 6
example:eggs = 2÷6. =²/6
2) to get the SI unit for 540 people ,multiply the SI unit by 540.
example:eggs ²/6×540. = 180
3)convert the answers to scientific notation
example:eggs =180. =1.8×10²
Identify the type of reaction in the following and define each of them. (i) Carbohydrates are broken down to form glucose. (ii) Tarnishing of copper. (iii) Heating of ferric oxide with aluminium powder. (iv) Blue colour of copper sulphate solution disappears when zinc dust is added to it. (v) Dilute sulphuric acid is adeed to sodium hydroxide solution .
Answer:
(i) hydrolysis; (ii) combination; (iii) single replacement;
(iv) single replacement; (v) double replacement
Explanation:
(i) Carbohydrates are broken down to form glucose
Carbohydrates must react with water to form glucose.
For example,
C₆H₁₁O₅-O-C₆H₁₁O₆ + H-O-H ⟶ 2C₆H₁₂O₆
maltose glucose
This is a hydrolysis reaction — the reaction of a compound in which a molecule of water breaks one or more bonds to form new substances.
The reaction is not a decomposition (a reaction in which a compound breaks down into two or more simpler substances), because two different molecules are involved.
(ii) Tarnishing of copper.
Cu + S ⟶ CuS
This is a combination or synthesis reaction — in which two or more substances combine to form a single new substance.
(iii) Heating of ferric oxide with aluminium powder
Fe₂O₃ + 2Al ⟶ Al₂O₃ + 2Fe
This is a single displacement or single replacement reaction — in which one element replaces another element in a compound.
Here, Al is replacing Fe in its oxide.
(iv) Blue colour of copper sulphate solution disappears when zinc dust is added to it
CuSO₄ + Zn ⟶ ZnSO₄ + Cu
This is a single displacement or single replacement reaction.
Here, Zn is replacing Cu in its sulfate.
(v) Dilute sulfuric acid is added to sodium hydroxide solution
H₂SO₄ + 2NaOH ⟶ Na₂SO₄ + 2H₂O
2H⁺, SO₄²⁻ + 2Na⁺OH⁻ ⟶ 2Na⁺, SO₄²⁻ + 2H-OH
This is a double displacement or double replacement reaction — in which the positive and negative ions of two ionic compounds exchange places to form two new compounds.
The Na⁺ ions are replacing the H⁺ ions in the sulfuric, forming sodium sulfate and water,
Suppose you carry out a titration involving 3.00 molar HCl and an unknown concentration of KOH. To bring the reaction to its end point, you add 35.3 milliliters of HCl to 105.0 milliliters of KOH. What is the concentration of the KOH solution?
Answer: The concentration of the KOH solution is 1.01 M
Explanation:
According to neutralization law:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1[/tex] = basicity of [tex]HCl[/tex] = 1
[tex]n_2[/tex] = acidity of KOH = 1
[tex]M_1[/tex] = concentration of HCl = 3.00 M
[tex]M_2[/tex] = concentration of KOH = ?
[tex]V_1[/tex] = volume of HCl = 35.3 ml
[tex]V_2[/tex] = volume of KOH = 105.0 ml
Putting the values we get:
[tex]1\times 3.00\times 35.3=1\times M_2\times 105.0[/tex]
[tex]M_2=1.01[/tex]
Thus the concentration of the KOH solution is 1.01 M
The Michaelis constant, Km, refers to the __________ at which a reaction proceeds at __________ of the maximum velocity. This constant most accurately reflects __________. The Michaelis constant, Km, refers to the __________ at which a reaction proceeds at __________ of the maximum velocity. This constant most accurately reflects __________. product concentration; one-half; structure of the substrate enzyme concentration; one-half; temperature optimum of the enzyme substrate concentration; one-half; the affinity of the substrate-enzyme interaction substrate concentration; one-fourth; pH optimum of the enzyme
Answer:
substrate concentration; one-half; the affinity of the substrate-enzyme interaction
Explanation:
The Michaelis constant, Km, refers to the substrate concentration at which a reaction proceeds at one-half of the maximum velocity. This constant most accurately reflects the affinity of the substrate-enzyme interaction.
Why do Group 12 elements have different properties than Group 13
elements?
A. They have different numbers of neutrons.
B. They have different numbers of valence electrons,
C. They have different numbers of protons.
D. They have different atomic numbers.
The group 12 elements have different properties than group 13 elements because both have different number of valence electron.
What is valence electron?The electron present in valence shell is called valence electron.
The electronic configuration group 12 and group 13 is given below.
Electronic configuration Group 12 = (n-1)d10 ns2
Electronic configuration Group 13 = ns2np1
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How many significant figures are there in 6.07x10^-15?
Answer:
3
Explanation:
6.07 has 3 digits and all are significant
Which condition must be met in order for an equation to be balanced? The elements in the reactants are the same as the elements in the products. There are fewer elements in the reactants than there are in the products. The number of atoms in the reactants is greater than the number of atoms in the products. The number of atoms in the reactants equals the number of atoms in the products.
Answer:
The number of atoms in the reactants equals the number of atoms in the products.
Explanation:
In every chemical reaction equation there are two sides; the reactants sides and the products side. The reactants side shows the species that combine to form the products. On both sides of the reaction equation, chemical species are found to be composed of atoms.
The major principle in balancing of chemical reaction equations is that the number of atoms of each element in the reactants side must be equal to the number of atoms of the same element on the products side. Once this condition is achieved, we can now say that the chemical equation is balanced.
Answer:
Answer D: The number of atoms in the reactants equals the number of atoms in the products.
Explanation:
Had the answer plus doing the quiz right now and got it right 100%
Question 7 of 25
What is an energy level?
A. The total energy possessed by all the electrons of an atom
B. The energy contained within the nucleus of an atom
C. The energy required to remove an electron from its nucleus
D. The energy possessed by an electron at a set distance from the
nucleus
SUBMIT
Answer:
d)the energy possessed by an electron at a set distance from the nucleus
A student has a piece of aluminum metal what is the most reasonable assumption a student can make about the metal
Answer:
- It could be stretched into a thin wire.Explanation:
As per the question, the most rational claim that the student can make about the aluminum metal is that 'it could be stretched into a thin wire' without breaking which shows its ductility. It is one of the most significant characteristics of a metal. Metals can conduct electricity in any state and not only when melted. Thus, option A is wrong. Options C and D are incorrect as metals neither have the same shape always nor do they break on hitting with a hammer. Therefore, option E is the correct answer.
Answer:
Yes, the other person is correct; the answer is E. It could be stretched into a thin wire.
Explanation:
Here is why it is NOT B:
"A briskly burning wood fire is plenty hot enough to melt aluminum. If it's just smoldering (like a lot of campfires) it won't create enough heat to melt aluminum."
Therefore, CAMPFIRES are not likely to melt aluminum if it is thrown in. Aluminum's melting point is 1,221 ° F. Typical campfires are about 900 ° F.
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30cm^3 of a dilute solution of Ca(OH)2 required 11 cm^3 of 0.06 mol/dm^. Hcl for complete neutralization. Calculate the concentration of the Ca(OH)^2 solution in mol/dm^3 and g/dm^3
Answer: Thus concentration of [tex]Ca(OH)_2[/tex] in [tex]mol/dm^3[/tex] is 0.011 and in [tex]g/dm^3[/tex] is 0.814
Explanation:
To calculate the concentration of [tex]Ca(OH)_2[/tex], we use the equation given by neutralization reaction:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]HCl[/tex]
[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is [tex]Ca(OH)_2[/tex]
We are given:
[tex]n_1=1\\M_1=0.06mol/dm^3\\V_1=11cm^3=0.011dm^3\\n_2=2\\M_2=?\\V_2=30cm^3=0.030dm^3[/tex] [tex]1cm^3=0.001dm^3[/tex]
Putting values in above equation, we get:
[tex]1\times 0.06mol/dm^3\times 0.011dm^3=2\times M_2\times 0.030dm^3\\\\M_2=0.011mol/dm^3[/tex]
The concentration in [tex]g/dm^3[/tex] is [tex]0.011mol/dm^3\times 74g/mol=0.814g/dm^3[/tex]
Thus concentration of [tex]Ca(OH)_2[/tex] is [tex]0.011mol/dm^3[/tex] and [tex]0.814g/dm^3[/tex]
Answer:
d
Explanation:
d
Assertion: When a strong acid is added to a buffer system consisting of a weak acid (HA) and its conjugate base (A-), the concentration of the conjugate base increases. Reason: A stoichiometric amount of the weak acid is converted to its conjugate base. Group of answer choices
Answer:
Both the assertion and reason are false
Explanation:
A buffer is a solution that resists changes in acidity and alkalinity. When a solution is buffered, it pH can only vary within a small range. A buffer is made up of a weak acid/base and its salt.
When a strong acid is added to a buffer solution, the conjugate base will react with the H+ from the strong acid to form the undissociated weak acid HA as follows; H+(aq) + A- (aq)→ HA(aq). Hence, H+ concentration decreases owing to its reaction with the A- thus the pH changes only slightly.
At the time when the strong acid should be added so here Both the assertion and reason are false
What is buffer?It is a solution that resists changes with respect to the acidity and alkalinity. When a solution should be buffered, it pH can only change within a small range. At the time when a strong acid should be added to a buffer solution, the conjugate base should be react with the H+ from the strong acid to form the undissociated weak acid.
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