Answer:
Exothermic reactions feel hot
Endothermic reactions feel cool
Explanation:
In an exothermic reaction, heat is given out by the system. The energy of the reactants is greater than that of the products hence the excess energy is given off as heat. The reaction vessel feels hot.
In an endothermic reaction, the energy of products is greater than that of the reactants hence energy is taken into the system and the reaction vessel feels cool.
The discharge of chromate ions (CrO42-) to sewers or natural waters is of concern because of both its ecological impacts and its effects on human health if the receiving water is later used as a drinking water source. One way in which chromate can be removed from solution is by its reaction with ferrous ions (Fe2+) to form a mixture of chromic hydroxide and ferric hydroxide solids [Cr(OH)3(s) and Fe(OH)3(s), respectively], which can then be filtered out of the water. The overall reaction can be represented as
CrO42- + 3 Fe2+ + 8 H2O --> Cr(OH)3(s) + 3 Fe(OH)3(s) + 4 H+
How much particulate matter would be generated daily by this process at a facility that treats 60 m3/h of a waste stream containing 4.0 mg/L Cr, if the treatment reduces the Cr concentration enough to meet a discharge limit of 0.1 mg/L?
Answer:
45727g
Explanation:
So, have the overall ionic equation given as the following;
CrO42^- + 3 Fe2^+ + 8 H2O ------> Cr(OH)^3(s) + 3 Fe(OH)^3(s) + 4 H^+.
So, we have (from the question) that the amount or quantity of the waste stream daily = 60m^3/h, and the waste stream daily contains waste stream containing = 4.0 mg/L Cr, and the discharge limit = 0.1 mg/L.
Step one: convert m^3/ h to L/h. Therefore, 60 m^3/h × 1000dm^3 = 60000 L/h .
Step two: Determine or calculate the the value of Cr used up.
The value of Car used up ={ 60,000 × ( 4.0 - 0.1) } ÷ 1000 = 234 g.
Step three: Determine or calculate the mass of Cr(OH)3 and the mass of Fe(OH)3.
The number of moles of Cr = 234/52 = 4.5 moles.
Molar mass of Cr(OH)3 = 103 g/mol and the molar mass of Fe(OH)3 = 106.8 g/mol.
Thus, the mass of Cr(OH)3 = 4.5 × 103 = 463.5 g.
And the mass of Fe(OH)3 = 13.5 × 106.8 = 1441.8 g.
Hence, the total = 463.5 g + 1441.8 g = 1905.3 g.
Step four: Determine or calculate the How much particulate matter would be generated daily.
The amount of the particulate that would be generated daily = 24 × 1905.3 = 45727g.
noble gas notation for titanium
Answer:
Titanium [Ar] 3d2 4s2
Explanation:
A species that has 13 protons and 10 electrons will be_____
Answer: Aluminum
Explanation:
Al3+ indicates an ion of aluminum having a charge of + 3. I.e., since an aluminum atom normally has 13 protons and 13 electrons, this ion has 10 electrons (-10 charge) and 13 protons (+ 13 charge) giving it a charge of + 3 (-10 + 13 = +3).
Answer:
Explanation:
Al3+ indicates an ion of aluminum having a charge of + 3. I.e., since an aluminum atom normally has 13 protons and 13 electrons, this ion has 10 electrons (-10 charge) and 13 protons (+ 13 charge) giving it a charge of + 3 (-10 + 13 = +3).
ccto.
Calculate the mass in grams for 3.28 moles of O2? Please show your work to receive credit.
Answer:
105 g O₂
Explanation:
Step 1: Define
Molar Mass O - 16.00 g/mol
Molar Mass O₂ - 2(16.00) = 32.00 g/mol
Step 2: Use Dimensional Analysis
[tex]3.28 \hspace{3} mol \hspace{3} O_2(\frac{32 \hspace{3} g \hspace{3} O_2}{1 \hspace{3} mol \hspace{3} O_2} )[/tex] = 104.96 g O₂
Step 3: Simplify
We are given 3 sig figs.
104.96 g O₂ ≈ 105 g O₂
the coefficient of 02 is needed to balance the equation C3h8+O2+3co2+4H20
Answer:The anwser is 5
Explanation:
Give Me An Atom With The Following Characteristics Lanthanide series
10. The density of aluminum is 2.70 g/mL. If the mass of a piece of aluminum is 244 grams, what is the volume of the aluminum?
Answer:
The answer is 90.37 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{244}{2.7} \\ = 90.370370...[/tex]
We have the final answer as
90.37 mLHope this helps you
When drawing the Lewis structure of a molecule, start by determining the total number of available valence based on each element's ___________ group number. Then, use the total number of electrons needed for each element to be stable, generally based on________ its charge, to determine the____________ ionic charge by finding the difference between the number of needed and available electrons divided by two.
Next, identify the central atom, which is the element with the __________ fewest valence electrons other than hydrogen. Finally, arrange the number of bonds around the central atom to fulfill the stable number of electrons for each element.
Answer:
Group number, octet's rule, total number of bonds and fewest valence electrons.
Explanation:
Hello,
For the given statement is answer is bolded:
"When drawing the Lewis structure of a molecule, start by determining the total number of available valence based on each element's group number. Then, use the total number of electrons needed for each element to be stable, generally based on the octet's rule its charge, to determine the total number of bonds by finding the difference between the number of needed and available electrons divided by two.
Next, identify the central atom, which is the element with the fewest valence electrons other than hydrogen. Finally, arrange the number of bonds around the central atom to fulfill the stable number of electrons for each element".
For the first one, it is widely known that the group number provides the number of valence electrons as nitrogen is in group VA and it has five valence electrons, chlorine is in grou´p VIIA and it has seven valence electrons and so on.
For the second one, it is also known that the octet's rule limit the amount of bonds as it has been demonstrated that each compound can hold up to 8 electrons overall excluding some exceptions.
For the third one, based on the octet's rule, an element must have as much bonds as missing electrons to complete eight, for instance, carbon has four valence electrons, so it need four bonds (each one providing one valence electron) in order to attain the octet.
Finally, the central atom must have the fewest number of valence electrons as it shows the other bonds and elements attaining the octet. Usually, the central atom is not demanded to get 8 electrons, for instance in AlCl₃, which is:
[tex]\ \ \ \ \ Cl-Al-Cl\\.\ \ \ \ \ \ \ \ \ \ \ \ \ |\\.\ \ \ \ \ \ \ \ \ \ \ \ Cl[/tex]
Has aluminum as the central one due to the fact that it has three valence electrons whereas chlorine seven and it does not attain the octet.
Best regards.
molecular formula of C4H5
Answer:
Cyclopropylmethylene
If equal volumes of a strong base and a weaker acid are mixed together, what would you expect the pH of the resulting salt to be
Answer:
Above 7
Explanation:
The equivalence point of any titration can be read off from the appropriate titration curve.
A titration curve is a plot of the pH of analyte against the volume of titrant added.
For a strong base and weak acid, the equivalence point lies above 7.
The pH of the resulting salt to be pH> 7 .
What does Equivalence point tell?The equivalence point of any titration can be read off from the appropriate titration curve. A titration curve is a plot of the pH of analyte against the volume of titrant added. It is a point in titration at which the amount of titrant added is just enough to completely neutralize the analyte solution. At the equivalence point in an acid-base titration.
For a strong base and weak acid, the equivalence point lies above 7.
Find more information about Equivalence point here:
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Which of these is a source of pollution caused by humans?
A)
volcances
B)
pesticides
lightning strikes
D)
biological decay
Answer:
biological decay
Explanation:
Hope this helps
the density of an 18.0 solution of ammonium sulfate is 1.10g/ml. What mass of Ammonium sulfate is required to prepare 275ml of this solution
Answer:
Therefore, 54.45 g of Ammonium sulphate is required
Explanation:
Molar mass of ammonium sulphate, (NH₄)₂SO₄ = 132 g/mol
Since density of solution is 1.10 g/ml, a 1 mL solution has mass = 1.10 g
275 mL solution will have a mass = 275 * 1.10 = 302.5 g
Since the solution is 18% ammonium sulphate by weight,
mass of ammonium sulphate present in 275 mL solution = 302.5 * 18/100
mass of ammonium sulphate present in 275 mL solution = 54.45 g
Therefore, 54.45 g of Ammonium sulphate is required
Zinc wire is added to an iron(II) nitrate solution.
Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if there is no reaction.
Answer:
Zn(s) + Fe(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Fe(s)
Explanation:
When metal zinc is added to an iron (II) nitrate solution, we can see the following redox reaction:
Zn(s) + Fe(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Fe(s)
Zinc is oxidized since its oxidation number increases from 0 to +2.
Iron is reduced since its oxidation number decreases from +2 to 0.
The same ball is hit again and experiences a net force of 3.5 N instead. What is the acceleration of the volleyball?
Answer:
I hope this helped :)
Explanation:
a=f/m
a=3.5N/.25 kg
a=14m/s2
The acceleration of the volleyball is 14 m/s²
A force is defined to be a pull or a push acting on an object. The force exerted on an object can be said to be determined if the mass of the object is known.
It can be calculated by using the expression;
Force (F) = mass (m) × acceleration (a)
From the given information;
The net force acting on the ball after it hits again = 3.5 NLet assume that the mass of the ball is 0.25 kg since it is not given∴
The acceleration of the above expression can be computed as:
acceleration (a) = Force (F) / mass (a)
acceleration (a) = 3.5 / 0.25
acceleration (a) = 14 m/s²
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what is the chimestry
Which of the following represents a species with 16 protons and 18 electrons? A) Ar B) S C) S²⁻ D) Si⁴⁻ E) S²⁺ Question 5 of 40
Answer:S²⁻
Explanation:
Sulphur is in group 16. The atomic number of sulphur is 16.
However, sulphur can accept two electrons to form the sulphide ion S²⁻ which contains 18 electrons, hence the answer provided above.
PLEASE PLEAS HELP Which of the following compounds is insoluble in water?
a) ZnSO4
b) K2SO4
c) Na2CO3
d) Ag2CO3
Answer:
Your answer is d
Explanation: silver carbonate Ag2CO3 is insoluble in water
Forty milliliter of a liquid has a mass of 80 grams. What is the density of this substance?
Answer:
2.00g/ml
Explanation:
If water has a density of 1.00g/ml, and theres
40ml of it, it would weigh 40g
The substance is twice as dense as water, making its density 2.00g/ml
plsss help!!!!! I'll give u brainlest and 10 points
Answer:
I would say it is true
Explanation:
Which element is classified as a noble gas?
Answer:
any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og). :)
Explanation:
Answer:
For edge, the answer is;
D. Xe
(Xenon)
Explanation:
edg- answers ;p
which dissolved first in acetone? food coloring or liquid paint?
Answer:
Liquid paint.
Explanation:
Liquid paints are dissolved first in acetone. Most of the food dyes are not soluble in acetone.
What is acetone?Acetone is an organic compound comes under the category of ketones. It contains a carbonyl group and can dissolve most of the organic solvents.
The active ends in acetone easily forms hydrogen bonds with other solvents with polar or nonpolar groups.
Xylene, benzene, toluene, aromatic azo dyes etc. are common components in paint. Which are easily miscible with acetone.
Hence, liquid paints dissolve in acetone and food dyes are hard o dissolve in it.
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A liquid has a volume of 62.7 mL and a density of 2.59 g/mL. What is its mass? (show all work)
Answer:
162.4
Explanation:
The formula for mass is density* volume so 62.7 multiplied by 2.59 equals 162.393. then you round so your anwser would be 162.4
3.54 millilelvin = ? kelvin
What was one main point of Dalton’s atomic theory?
A. That atoms were made up of positive and negative charges
B. That atoms changed as they formed compounds
C. That atoms has a nucleus at the center
D. That atoms made up the smallest form of matter
The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
What is Dalton's Atomic Theory ?
The 5 main points of Dalton's Atomic theory was ;
Elements are composed of extremely small particles called atoms that are indivisible and indestructibleAll atoms of a given element are identical; they have the same size, mass, and chemical propertiesAtoms of 1 element are different from the atoms of all other elementsCompounds are composed of atoms of more than 1 element. The relative number of atoms of each element in a given compound is always the same.Chemical reactions only involve the rearrangement of atoms. Atoms are not created or destroyed during chemical reactions.Therefore, The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
Learn more about Atom here ;
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Answer:
D is correct
Explanation:
Which element contains one set of paired and three unpaired electrons in its fourth and outer main energy level?
Explanation:
Phosphorus (P) because of the 5 valence electrons total, 3 of them are in the 3p sublevel, and according to Hund's rule, they "single-fill" each orbital first.
Violet light has a wavelength of 4.50 x 10-12 m. What is the frequency?*
3 points
1.5 x10^20 1/s
0.0135 1/s
6.77x10^19 1/5
3x10^8 1/s
Green light has a frequency of 6.73 x 1014 1/s. What is the wavelength?*
3 points
2.24x10^6 m
4.46x10^-7 m
2.02 x 10^23 m.
4.95 x 10^-24 m
3 points
What is the energy (Joules) of violet light with a frequency = 3.43 x 10^14
1/s? *
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
2.27 x 10^-19 J
Answer:
Frequency = 6.67x10¹⁹ s⁻¹
Wavelength = 4.46x10⁻⁷m
e = 2.27x10⁻¹⁹J
Explanation:
To convert frequency to wavelength and vice versa we use the equation:
Wavelength = Speed of light / Frequency
Speed ligth is 3x10⁸m/s
For a wavelength of 4.50x10⁻¹²m:
4.50x10⁻¹²m = 3x10⁸m/s / Frequency
Frequency = 3x10⁸m/s / 4.5x10⁻¹²m
Frequency = 6.67x10¹⁹ s⁻¹For a frequency of 6.73x10¹⁴s⁻¹:
Wavelength = 3x10⁸m/s / 6.73x10¹⁴s⁻¹
Wavelength = 4.46x10⁻⁷mAnd energy, e, from frequency, is obtained as follows:
e = h ₓ frequency
Where h is Planck's constant, 6.626x10⁻³⁴J*s
e = 6.626x10⁻³⁴J*s*3.43x10¹⁴s⁻¹
e = 2.27x10⁻¹⁹Jgive reason deliquescent substance truns into liquid when exposed to atmosphere air
The atoms of which element will gain electrons to form an ion?
oxygen
calcium
lithium
mercury
Explanation:
Oxygen will gain electrons to form ion (O²⁻).
Calcium loses electron to form ion (Ca²⁺)
Lithium loses electron to form ion (Li⁺)
Mercury loses electron to form ion (Hg²⁺)
Here it is stated in question that the element will gain electron it means electron bears negative charge.
Therefore,
Option A is correct ✔.
Complete the reactions of Sn(II) and Sn(IV), and be sure that the reactions are balanced. Do not include the phases (liquid, aqueous, etc.). If no reaction occurs, leave the products side of the equation
completed reaction: SnBr2+PbBr4⟶
completed reaction: SnBr4+PbBr2⟶
Select the statements that are true about the reactions.
A. PbBr4 is more stable than PbBr2.
B. The inert‑pair effect renders Sn(II) as the more stable oxidation state of tin.
C. Sn(IV) is the most stable oxidation state of tin.
D. The inert‑pair effect renders Pb(II) as the more stable oxidation state of lead.
Answer:
The Inert Pair effect renders Pb(II) as the more stable oxidation state of lead
Explanation:
SnBr4 + PbBr2 ---> SnBr2 + PbBr4
SnBr2 + PbBr4 ---->
The Inert pair effect is mostly observed between group 15-17 in the periodic table. It leads to stability of the lower oxidation state of an element.
The reason for the Inert pair effect is that the s electrons become Inert due to poor shielding of the d and f-electrons. The Inert pair effect is a tendency of the s electrons not to participate in bonding (remain an Inert pair).
Owing to the Inert pair effect, Pb II is more stable than Pb IV
When you cook food in a hot pan , which statement is correct? Energy from the food is transferred to the pan or energy from the food is transferred to the food.
Answer:
Not to sure! I think energy from the pan is transferred to the food? Maybe.
Explanation: