Answer:
case1.
The addition of acid and base leads to a change in pH of the water when adding to deionized water due to fact that acid and bases dissociated in dissolving in water. If the H+ ion increases in the water as acid addition hikes it, it will result in decreasing the pH value. The intensity of the acid also affects the dissociation of the ions.
case2
Buffers are normally formed by weak acid and its conjugate base, and adding acid to the buffer it absorbs the H+ ions so the pH will be lower and adding base or increase of OH- conjugate base resists the pH value to increase.
Suppose an EPA chemist tests a 250.mL sample of groundwater known to be contaminated with nickel(II) chloride, which would react with silver nitrate solution like this: NiCl2(aq) + 2AgNO3(aq) → 2AgCl(s) + NiNO32(aq) The chemist adds 15.0mM silver nitrate solution to the sample until silver chloride stops forming. He then washes, dries, and weighs the precipitate. He finds he has collected 5.8mg of silver chloride. Calculate the concentration of nickel(II) chloride contaminant in the original groundwater sample. Round your answer to 2 significant digits.
Answer:
0.0010 w/v %
Explanation:
Based on the reaction:
NiCl₂(aq) + 2AgNO₃(aq) → 2AgCl(s) + Ni(NO₃)₂(aq)
Finding the moles of AgCl produced we can find the moles of NiCl in the reaction medium and its mass:
Moles AgCl -Molar mass: 143.32g/mol-:
5.8mg = 5.8x10⁻³g * (1mol / 143.32g) = 4.047x10⁻⁵ moles AgCl
Moles NiCl₂:
4.047x10⁻⁵ moles AgCl * (1mol NiCl₂ / 2mol AgCl) = 2.023x10⁻⁵ moles NiCl₂
Mass NiCl₂ -Molar mass: 129.60g/mol-:
2.023x10⁻⁵ moles NiCl₂ * (129.60g / mol) = 2.62x10⁻³g of NiCl₂ are produced.
And the concentration in w/v% is:
2.62x10⁻³g NiCl₂ / 250mL * 100 =
0.0010 w/v %Which of the following chemical substances has a triple
covalent bond?
A. carbon dioxide (CO2)
B. oxygen (0)
C. carbon monoxide (CO)
D. water (H,0)
Answer:
C. Carbon monoxide
Explanation:
Chemical substance which has a triple covalent bond is carbon monoxide.
What is a covalent bond?Covalent bond is defined as a type of bond which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.
Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.
Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.
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How many grams of air are required to complete the combustion of 120 g of phosphorous to diphosphorous pentoxide, assuming the air to be 23% oxygen by mass?
Answer:
Explanation:
522 g
Explanation:
Your starting point here will be the balanced chemical equation for this combustion reaction
4
P
(s]
+
5
O
2(g]
→
2
P
2
O
5(s]
Notice that you have a
4
:
5
mole ratio between phosphorus and oxygen. This means that, regardless of how many moles of phosphorus you have, the reaction will always need
5
4
time more moles of oxygen gas.
Use phosphorus' molar mass to determine how many moles you have in that
93.0-g
sample
93.0
g
⋅
1mole P
30.974
g
=
3.0025 moles P
Use the aforementioned mole ratio to determine how many moles of oxygen you would need for many moles of phosphorus to completely take part in the reaction
3.0025
moles P
⋅
5
moles O
2
4
moles P
=
3.753 moles O
2
______ occur between molecules that have permanent intramolecular differences in elecronegativity.
A. Dipole-dipole interactions
B. Dispersion forces
C. Hydrogen bonds
Answer:
Dipole-dipole interactions
Explanation:
Draw the structure formula for
1-ethyl-2,3-dimethylbenzene
Please help me
Answer:
Please see the attached picture.
Explanation:
1) Draw a benzene ring
2) On the first carbon, add a CH₂CH₃ (known as ethyl) since its location number is 1.
3) 'Dimethyl' refers to 2 methyl (CH₃) branches. The location numbers are 2 and 3, thus add a CH₃ on the 2nd and 3rd carbons.
Which of this is formed when a metal reacts with steam ? *
Carbon dioxide
A Salt
An oxide
A metal hydroxide
What rock forms from magma oozing onto the surface?
a. Igneous rock
b. Metamorphic rock
C. Sedimentary rock
d. Lava rock
4. What is the specific heat of a substance if 5800 joules is
released in a 250 gram sample that will cool the substance from
60 degrees to 45 degrees?
Answer: 23.2
Explanation:
How many grams of water can be made from 6 moles of oxygen
Fossil fuels are made up of organisms that died millions of years ago. Which best describes this source of energy
help someone i need this
During a hurricane, what effect can the ocean have on the beach?
What is the percent composition of a 16.75 g sample of a compound containing 14.02 g oxygen and 2.73 g hydrogen? Select the correct answer below: 83.7% oxygen, 16.3% hydrogen O 17% oxygen, 13% hydrogen O 68.2% oxygen, 31.8% hydrogen 89.5% oxygen, 10.5% hydrogen
Answer:
83.7% oxygen, 16.3% hydrogen
Explanation:
Mass of compound = 16.75 g
Mass of Oxygen = 14.02 g
Mass of Hydrogen = 2.73 g
Percentage composition = Mass of element / Mass of compound 100%
Percentage composition of Oxygen = 14.02 g / 16.75 g * 100%
Percentage composition of Oxygen = 0.837 * 100 = 83.7%
Percentage composition of Hydrogen = 2.73 g / 16.75 g * 100%
Percentage composition of Hydrogen = 0.163 * 100 = 16.3%
The correct option is;
83.7% oxygen, 16.3% hydrogen
Answer:
83.7% oxygen, 16.3% hydrogen
Explanation:
To determine the percent composition we can divide, our mass by total mass and afterwards, multiply by 100.
(Mass of O / Total mass) . 100 = % O
(Mass of H / Total mass) . 100 = % H
Remember that:
% O + % H = 100
Mass of O / Total mass + Mass of H / Total mass = 1
(14.02 g / 16.75g) . 100 = 83.7 %
(2.73 g /16.75g) . 100 = 16.3 %
What is the molar mass of AIC13?
why do you think season will impact the size of a rabbit population
Please answer this question
Answer:
K^2O
Explanation:
I remember a question like this one and I got it right its K^2O
(aka its C)
Balance equation mg3n2+h2so4=mgso4+(nh4)2
Answer:
Mg₃N₂ + 4 H₂SO₄ ⇒ 3 MgSO₄ + (NH₄)₂SO₄
Explanation:
To balance an equation, you need to make both sides of the equation have equal number of each element. Also, I think that you didn't write the whole equation since the reaction you gave is not likely.
Mg₃N₂ + 4 H₂SO₄ ⇒ 3 MgSO₄ + (NH₄)₂SO₄
What is the purpose of the scientific method?
A. To use an experiment to test a scientific theory
B. To make a guess in order to prove a hypothesis
C. To remove any source of bias in an experiment
D. To provide a reliable answer to a specific question
Answer:
B. To make a guess in order to prove a hypothesis.
Explanation:
What does Ra Ra Ah Ah Ah Ro Ma Ro Ma Ma Ga Ga O La La mean?
Answer:
They are symbols of elements.
Ra is the symbol of the element Radium
Ah is the symbol of the element Arrhenium
Ma is the symbol of the element Molybdenum
Ga is the symbol of the element Gallium
La is the symbol of the element Lanthanum
Answer:
Ra is the symbol of the element Radium
Ah is the symbol of the element Arrhenium
Ma is the symbol of the element Molybdenum
Ga is the symbol of the element Gallium
La is the symbol of the element Lanthanum
Explanation:
They are elements
Which of the following statements best describes a
mixture?
O A substance that contains two or more elements chemically joined
O A substance that contains two or more elements not chemically joined
O A substance that contains only one type of atom
O A substance that contains two or more compounds or elements that are
not chemically joined.
In the process of performing a spectrophotometric determination of iron, an analyst prepares a calibration curve using a single-beam spectrophotometer. After preparing the calibration curve, the analyst drops and breaks the cuvette. The analyst acquires a new cuvette, measures the absorbance of the sample, and determines the %w/w Fe in the sample. Does the change in cuvette lead to a determinate error in the analysis
Answer:
Yes.
Explanation:
Yes, the change in cuvette lead to a determinate error in the analysis if the different cuvette is used for the analysis because the amount of liquid sample that is used has different volume. If both cuvette are of the same type and has no difference in their structure and size then there is error occurs in the analysis but if both cuvette are different from one another then the error will occur in the analysis. because the amount of liquid that is used has different volume.
Scientists have been classifying living organisms for centuries. In the 1970s, organisms were classified in a five-kingdom
classification scheme. However, two decades later, organisms called Archaebacteria were discovered. This led to a three-domain
system of classification that combined some of the previous five-kingdom schemes.
What does this change in classification methods demonstrate?
Answer:
Classification is important because it allows scientists to identify, group, and properly name organisms via a standardized system (Linnaeus Taxonomy); based on similarities found in the organisms DNA/RNA (genetics), Adaptations (Evolution), and Embryonic development (Embryology) to other known organisms to better.
Hope I helped!!
The five kingdoms of classifications were animalia, plant, fungi, protista and monera. Later Archaebacteria was discovered and this led to the 3 kingdom classification animalia, plantae and protista.
What is biological classification?There are different classifications for living things based on their nature, body and origin. The kingdom animalia includes all the animals including human beings.
Kingdom plante includes all the plants and kingdom fungi, protista and monera are of microbes. Later the discovery and study of Archaebacteria proved that they exhibit similar body type and functions as bacterias.
After that, scientists turned into 3 kingdom classification, where all the prokaryotic organisms including protists, monera and fungi classified as one. The evolutional changes originated in them made this classification.
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A triangle has one angle that measures 81° and one that measures 37° what is the measure of a third angle
HELP I WILL GIVE YOU BRAINLIST!!!
Pick one substance (ex: water and table salt) and compare two of the atoms connected to each other (ex: H and O, Na and Cl) and answer the following questions for each pair:
1)Are they close or far away from each other on the periodic table?
Do they have similar atomic radii?
2)Do they have a large or small difference in ionization energy? What about for electron affinity?
The equivalence point in a titration refers to the point when
A. the mł of the acid equals the mL of the base.
B. the molarity of the acid used in the reaction equals the molarity of the base used in the reaction.
C. the number of moles of one reactant reacts completely with the moles of the other reactant.
D. the acid in the flask turns clear.
Answer:
C) the number of moles of one reactant reacts completely with the moles of the other reactant.
Explanation:
it's right put it
Answer:
C
Explanation:
Liquids B and C are partially miscible at 25 oC. When one starts with 1 mol of C at 25 oC and isothermally adds B a little at a time, a two-phase system first appears when a bit more than 0.125 mol of B has been added; continuing to add B, one finds the two-phase system becomes a one-phase system when a total of 3 mol of B has been added. For a system consisting of 2.5 mol of B and 2 mol of C at 25 oC, find the number of moles of B and of C present in each phase.
Answer:
[tex]0.8\overline 3[/tex] moles of A and 2.5 moles of B in the one-phase system
[tex]1.1 \overline 6[/tex] moles of A and [tex]0.1458 \overline 3[/tex] moles of B in the two-phase system
[tex]0.3541 \overline 6[/tex] moles of B remains in the system
Explanation:
The given parameters are;
The extent of miscibility of liquid B and C = Partially miscible
The number of moles of liquid B added to 1 mole of liquid A that forms a two-phase system = 0.125 mol of liquid B
The number of moles of liquid B added to 1 mole of liquid A that forms a one -phase system = 3 moles of liquid B
Whereby the system consist of 2.5 mol of B and 2 mol of C at 25°C, we have;
The 1 mole of A mixes with 3 moles of B to form a single phase solution
Therefore;
2.5 moles of B will mix with (1/3)×2.5 moles of A = 5/6 moles of A
The remaining number of moles of A in the system = 2 - 5/6 = 7/6 moles of A
Similarly, we have;
At least, 0.125 mole of B combines with 1 mole of A to form a two-phase system
7/6 moles of A will combine with 7/6 × 0.125 = 7/48 moles of B to form a two-phase system
The number of moles of B left = 0.5 - 7/48 = 17/48 = 0.3541[tex]\overline 6[/tex] moles of A
Therefore, we have;
5/6 moles of A and 2.5 moles of B in the one-phase system
7/6 moles of A and 7/48 moles of B in the two-phase system
17/48 moles of B remaining in the system
Zinc metal reacts with copper sulfate through the following
reaction:
Zn + CuSO4 → Cu + ZnSO4
The percent yield for a reaction in which 32.5 g of Zn is reacted
in excess CuSO4 solution is 85.0 %. What is the actual yield of
copper of this reaction?
g
Answer:26.9
Explanation:
State the coefficient required to correctly balance the following chemical equation:
_____ Ca3(PO4)2+ _____ NaCl ---------> _____ Na3PO4 + _____ CaCl2
Answer:
1 Ca3(PO4)2+ 6 NaCl ---------> 2 Na3PO4 + 3 CaCl2
What is the atomic mass of element XX if 3.6 moles of the substance has a mass of 192 grams?
Answer:
53.3g/mol
Explanation
Moles=mass/molar mass
Molar mass= mass/moles
Molar mass= 192/3.6
= 53.3
How many moles of ethanol are produced starting with 500.g glucose?
C6H12O6 → 2 C2H5OH + 2 CO2
5.55 mol C₂H₅OH
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TablesMolesStoichiometry
Using Dimensional AnalysisAnalyzing Reactions RxNExplanation:Step 1: Define
[RxN - Balanced] C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂
[Given] 500. g C₆H₁₂O₆ (Glucose)
[Solve] moles C₂H₅OH (Ethanol)
Step 2: Identify Conversions
[RxN] 1 mol C₆H₁₂O₆ → 2 mol C₂H₅OH
[PT] Molar mass of C - 12.01 g/mol
[PT] Molar Mass of H - 1.01 g/mol
[PT] Molar Mass of O - 16.00 g/mol
Molar Mass of C₆H₁₂O₆ - 6(12.01) + 12(1.01) + 6(16.00) = 180.18 g/mol
Step 3: Stoichiometry
[DA] Set up conversion: [tex]\displaystyle 500 \ g \ C_6H_{12}O_6(\frac{1 \ mol \ C_6H_{12}O_6}{180.18 \ g \ C_6H_{12}O_6})(\frac{2 \ mol \ C_2H_5OH}{1 \ mol \ C_6H_{12}O_6})[/tex][DA} Multiply/Divide [Cancel out units]: [tex]\displaystyle 5.55001 \ mol \ C_2H_5OH[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
5.55001 mol C₂H₅OH ≈ 5.55 mol C₂H₅OH