Answer:
b. 0.27 M ammonia + 0.38 M ammonium nitrate.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to bear to mind the fact that buffest must be prepared by using either of the following pairs:
weak acid/conjugate base
weak base/conjugate acid
So that the pH might be set constant. In such a way, since a. shows two salts, c. a strong acid with a neutral base, d, shows two acids and e. a strong base with a neutral base, we infer the correct buffer is b. 0.27 M ammonia + 0.38 M ammonium nitrate because it has a weak base (ammonia) and its conjugate acid, ammonium.
Regards!
1. How many atoms of chlorine are present in 1.70x1023 molecules Cl2?
Explanation:
the answer is in the image above
12.0: A
Mention three body fluids that are alkaline in nature
Atoms of element X have 12 times the mass of atoms of oxygen, and atoms of oxygen have 16 times the mass of atoms of hydrogen. What is the mass of atoms of element X on a scale on which atoms of hydrogen have a mass of 1?
A. 16/12
B. 12/16
С. 12 x 16
D. 16-12
E. 1216
Answer:
C. 12 × 16
Explanation:
Let mH be the mass of atoms of hydrogen and mO be the mass of atoms of oxygen. The atoms of oxygen have 16 times the mass of atoms of hydrogen. That is,
mO = 16 mH [1]
Let mX be the mass of the atoms of X. Atoms of element X have 12 times the mass of atoms of oxygen. That is,
mX = 12 mO [2]
If we substitute [1] in [2], we get
mX = 12 × 16 mH
If mH is 1, we get,
mX = 12 × 16 × 1
mX = 12 × 16
g Suppose you are titrating vinegar, which is an acetic acid solution of unknown concentration, with a sodium hydroxide solution according to the equation H C 2 H 3 O 2 + N a O H ⟶ H 2 O + N a C 2 H 3 O 2 If you require 30.01 mL of 0.1798 M N a O H solution to titrate 10.0 mL of H C 2 H 3 O 2 solution, what is the molar concentration of acetic acid in the vinegar? Type answer:
Answer: The molar concentration of acetic acid in the vinegar is 0.539 M.
Explanation:
The formula used is:
[tex]M_1V_1=M_2V_2[/tex]
where,
[tex]M_1[/tex] and [tex]V_1[/tex] are the concentration and volume of base.
[tex]M_2[/tex] and [tex]V_2[/tex] are the concentration and volume of an acid.
Given:
Molar concentration of NaOH = 0.1798 M
Volume of NaOH = 30.01 mL
Volume of acetic acid = 10.0 mL
Now putting all the given values in the above formula, we get:
[tex]M_1V_1=M_2V_2\\\\0.1798M\times 30.01mL=M_2\times 10.0mL\\\\M_2=0.539M[/tex]
Thu, the molar concentration of acetic acid in the vinegar is 0.539 M.
What is the difference between a physical change and a chemical change. Give an example of each.
Answer:
A physical change is a change in form.
A Chemical change is a change in materials.
Explanation:
Example of a physical change would be an ice cube meting.
Example of a chemical change would be mixing food coloring into a cup of water.
list some applications of chemistry in your dail life
Chemistry and chemical reactions are not just limited to the laboratories but also the world around you.
Chemistry in Food Production:
Plants produce food for themselves through photosynthesis; which is a complex chemical reaction in itself. The chemical reaction that takes place in photosynthesis is the most common and vital chemical reaction.
6 CO2 + 6 H2O + light → C 6H12O6 + 6 O2
Chemistry in Hygiene:
Right before you consume your food, you make it a point to wash your hands with soap. Isn’t it? The cleaning action of soap is based on its ability to act as an emulsifying agent. Soaps are fatty acids salts of sodium or potassium; produced by a chemical reaction called saponification. Soaps interact with the grease or oil molecule, which, in turn, results in a cleaner surface.
The Chemistry of an Onion:
Ever wondered why you shed tears while chopping an onion? This also happens because of the underlying chemistry concepts. As soon as you slice an onion, sulfenic acid is formed from amino acid sulfoxides. Sulfenic acid is responsible for the volatile gas, propanethiol S-oxide, that stimulates the production of tears in the eyes.
Chemistry in Baking:
Who does not like to eat fluffy freshly baked bread? Baking soda is an efficient leavening agent. The addition of baking soda to food items before cooking leads to the production of carbon dioxide (CO2); which causes the foods to rise. This whole process of rising of baked good is called chemical leavening.
Chemistry in Food Preservatives:
In case you ever read the ingredients on the bottle of ketchup, jams or pickles, you might be surprised to see a never-ending list of chemicals. What are they? These chemicals are called food preservatives; which delay the growth of microorganisms in foods. The chemical food preservatives not only prohibit the growth of bacteria, virus, fungi but also hinder the oxidation of fats, which is responsible for making the foods rancid. The most common chemical food preservatives are sodium benzoate, sorbic acid, potassium sorbate, calcium sorbate, sodium sorbate, propionic acid, and the salts of nitrous acid.
Chemistry in Digestion
The moment you put food in your mouth, a number of different chemical reactions start in your digestive tract. Saliva contains the enzyme amylase, which is responsible for breaking down carbohydrates, the stomach starts producing hydrochloric acid, the liver releases bile and the list of compounds released during digestion goes on. How do they work? All these enzymes undergo chemical reactions so that proper digestion, as well as assimilation of the food, occurs.
The Working of a Sunscreen
Before going out on a sunny day, you make it a point to wear sunscreen. Even the principle, behind the working of a sunscreen, has a chemistry background. The sunscreen uses a combination of organic and inorganic compounds to act as a filter for incoming ultraviolet rays. Sunblocks, on the other hand, scatter away UV light; so that it is unable to penetrate deep into the skin. Sunblocks contain complex chemical compounds like zinc oxide or titanium oxide, which prevent the UV rays to invade deeper into the skin.
Chemistry in Rust Formation
With time, your iron instruments start developing an orange-brown flaky coating called rust. The rusting of iron is a type of oxidation reaction. The atoms in the metal iron undergo oxidation and reduction; causing rusting. The formation of verdigris on copper and the tarnishing of silver are also the other everyday examples of chemical reactions. The chemical equation underlying rusting is:
Fe + O2 + H2O → Fe2O3. XH2O
Hope it helps.
An aqueous solution containing 5.72 g
of lead(II) nitrate is added to an aqueous solution containing 5.85 g
of potassium chloride. The reaction goes to completion, but some was lost in the process of washing and drying the precipitate. The percent yield for the reaction is 81.9%
. How many grams of precipitate is recovered? How many grams of the excess reactant remain? Assume the reaction goes to completion.
Answer:
3.93g are recovered
Explanation:
Pb(NO3)2 reacts with KCl as follows:
Pb(NO3)2 + 2KCl → 2KNO3 + PbCl2
To solve this question we need to find the moles of each reactant in order to find the limiting reactant:
Moles Pb(NO3)2 -Molar mass: 331.2 g/mol-
5.72g * (1mol/331.2g) = 0.01727 moles
Mole KCl -Molar mass: 74.5513g/mol-
5.85g * (1mol/74.5513g) = 0.07847 moles
For a complete reaction of 0.07847 moles of KCl are required:
0.07847 moles KCl * (1mol Pb(NO3)2 / 2mol KCl) = 0.03923 moles Pb(NO3)2
As there are just 0.01727 moles, Pb(NO3)2 is limiting reactant. Assuming 100% of yield:
Moles PbCl2 = Moles Pb(NO3)2
Mass PbCl2 -Molar mass: 278.1g/mol-
0.01727 moles * (278.1g / mol) = 4.80g
As percent yield is 81.9% = 0.819, the mass of PbCl2 recovered was:
4.80g * 0.819 = 3.93g are recovered
How do we fix climate change?
The biggest problem of course is conspiracy theorys. Some say it is just a hoxe when really their chidrin or grandchidrin will sufer greatly from it. How do we educate ourselfs better?
Answer:
Hi so your answer is that to helping fix the climate change you have to : speak up , power your home with renewable engery , reduce water waste , dont waste food , and finally invest energy .
Explanation:
Really hope i helped , have a nice day :)
Answer:
we can reduce air pollution,which is one of the main cause of climate change.Climate change is not a hoxe if it is not attending the upcoming generations will suffer greatly.
PLZZZZZZZZ HELPPPPPP
Answer:
482
Explanation:
Consider the following events that take place when rip currents occur.
A. Waves travel to the beach.
B. Waves are trapped by the sandbars.
C. Waves reach the shore and go back to the ocean.
D. Waves speed up and flow between the sandbars.
E. Waves are broken by the sandbars.
Which list shows the order of events in the production of rip currents?
A mixture of coarse sand and sugar is 45.0 percent sand by mass. 120.0 grams (g) of the mixture is placed in a fine-mesh cloth bag and dunked repeatedly in Lake Michigan. After drying, the mass of the contents of the bag equals: ________.
A. 66.0 g
B. 120.0 g
C. 65.0 g
D. 72.00 g
E. 54.0 g
Answer:
Option E
Explanation:
From the question we are told that:
Amount of sand in percentage [tex]s_p=45%[/tex]
Sample size[tex]n=120g[/tex]
Note:After being dumped in the river repeatedly the sugar melts away leaving behind the insoluble sand
Generally the equation for Amount of sand content is mathematically given by
[tex]X=n*s_p[/tex]
[tex]X=120*\frac{45}{100}[/tex]
[tex]X=54g[/tex]
Therefore
After drying, the mass of the contents of the bag equals
[tex]X=54g[/tex]
Option E
Which event is an example of melting?
A. Wax drips down the side of a lit candle.
B. Perspiration dries on a person's skin.
C. Rain turns to ice pellets.
D. A mirror fogs up when someone takes a hot shower.
I’m just curious tbh
Answer:
A. Wax drips down the side of a lot candle.
Explanation:
The chemical change from solid to liquid. This is a combustion reaction, so carbon dioxide gas and water vapour is also produced but you can't see them
Answer:
A. Wax drips down the side of a lot candle.
Explanation:
What is the observation of heating of iodine crystals
Answer:
On heating, the van der Waals dispersion forces existing then will easily break as it has a low boiling point and sublimates into gas. On heating iodine in the test tube, iodine evolves as violet fuming gas.
Explanation:
The literature values listed for the unknowns in this assignment are from either the Merck Index or the CRC Handbook, the two most used reference handbooks. However, the values tend to vary slightly across literature sources and sometimes the temperatures are given as ranges. Give at least one reason for the variations in these reported temperatures.
In general, the boiling points of compounds increase down a group in the periodic table. The melting points and boiling points for the hydrogen compounds of group 6A elements are in the table below.
Melting point (0C) Boiling point (oC)
H2O 0.0 100.0
H2S -82.0 -60.0
H2Se -65.7 -41.2
H2Te -49.0 -2.2
Answer:
See explanation
Explanation:
One of the important trends in the periodic table is electronegativity. Electro negativity decreases down the group and increases across the period. This trend has important consequences on the observed properties of the compounds of elements in a particular group in the periodic table.
As we move down in group 6A, the electro negativity of the elements elements the group decrease and as such, the magnitude of intermolecular hydrogen bonding between the molecules also decrease accordingly. Hydrogen bonds occur between
molecules of a substance when hydrogen is covalently bonded to an electronegative element. Hydrogen bonding is responsible for the high melting and boiling points of small molecules such as water which contain the highly electronegative oxygen atom.
So, as we move down the group there is lesser intermolecular hydrogen bonding between the hydride molecules of group 6A elements resulting in the observed trend in melting and boiling points of the hydrides.
The weaker hydrogen bonds that occurbetween molecules of group 6A hydrides lead to a steady decrease in melting and boiling points of the hydrides of group 6A elements as we move down the group.
How many moles of water are produced if 3.30 moles of N20 is
produced? NH4NO3 --> N20 + 2 H2O (mole to mole conversion) 1 step
Answer:
The netto reaction equation is:
2 OH- + 2H+ = 2 H2O
So the answer is 2 moles.
Identify the bronsted-lowry acid and the bronsted-lowry base in this reaction on the left side of each of the following equations, and also identify the conjugate acid and conjugate base of each on the right side.
mathrm { NH } _ { 4 } ^ { + } ( a q ) + mathrm { CN } ^ { - } ( a q ) rightleftharpoons mathrm { HCN } ( a q ) + mathrm { NH } _ { 3 } ( a q )
Answer: [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid
Explanation:
According to Bronsted and Lowry's theory:
An acid is defined as a proton donor while a base is defined as a proton acceptor.
In a chemical reaction, an acid loses a proton to form a conjugate base while a base accepts a proton to form conjugate acid.
For the given chemical reaction:
[tex]NH_4^+(aq)+CN^-(aq)\rightleftharpoons HCN(aq)+NH_3(aq)[/tex]
[tex]NH_4^+[/tex] is losing a proton thus it is an acid to form [tex]NH_3[/tex] which is its conjugate base
[tex]CN^-[/tex] is gaining a proton thus it is a base to form [tex]HCN[/tex] which is its conjugate acid
Hence, [tex]NH_4^+[/tex] is an acid, [tex]CN^-[/tex] is a base, [tex]NH_3[/tex] is conjugate base and [tex]HCN[/tex] is conjugate acid
What is the pCu of the resulting solution if 20.00 mL of 0.08 M EDTA (H4Y) is added to 15.00 mL of 0.10 M CuSO4 and buffered at pH 10? The Kf’ for complex CuY2- is 2.21 x 1018
Answer:
The answer is "5.4".
Explanation:
[tex]BoH + HCL =BCL +H_2o \\\\At eq \\\\N_1V_1=N_2V_2 \\\\v_2=20 \ ml\\\\[BCL]=\frac{20 \times 0.08}{20+20}=0.04\\\\pH = \frac{1}{2} [pkw - pk_b - \log e]\\\\pk_b = 2 pH - Pkw + \Log C\\\\pK_b=5.4[/tex]
Which of the following is not generally a characteristic of metal?
Ductility
O
Malleability
High melting point
Low boiling point
For the iron thiocyanate system, what is the value of the equilibrium constant, Kc, if the following are the concentrations of all species present. Provide your answer to three digits after the decimal.
FeSCN2+ 0.501
Fe3+ 0.494
SCN- 0.639
Answer:
Kc = 0.630
Explanation:
The equilibrium of the thiocyanate system occurs as follows:
FeSCN²⁺(aq) ⇄ Fe³⁺(aq) + SCN⁻(aq)
And equilibrium constant, kc, is:
Kc = [SCN⁻] [Fe³⁺] / [FeSCN²⁺]
Replacing with the gven concentrations:
Kc = 0.639M*0.494M / 0.501M
Kc = 0.63013. The attraction between water molecules and an Na+
ion or a Cl- ion occurs because water molecules are
A) linear
B) symmetrical
C) polar
D) nonpolar
Answer:
C) Polar
Explanation:
The correct answer is polar
The attraction of sodium and chloride ions by the water is mediated by the polar nature of water. Thus, option C is correct.
What is polarity?The polarity is given as the formation of the partial positive and negative charge over the species in the ionization process.
Water molecule is having one hydrogen bounded with 2 oxygen atoms, and oxygen being more electronegative develops a partial negative charge, while hydrogen develops a partial positive charge.
The positive charge hydrogen and the negative charge oxygen attracts the opposite charge sodium and chloride ions. Thus, the attraction is mediated due to the polar nature of water. Hence, option C is correct.
Learn more about polarity, here:
https://brainly.com/question/3184550
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atomic number of element is 15 write a formula of an oxide
Answer:
Atomic Number. 15=phosphorus
Valency=3
So, Oxide=P203
A 14.570 g sample of CaCl2 was added to 12.285 g of K2CO3 and mixed in water. A 3.494 g yield of CaCO3 was obtained.
What is the limiting reagent?
-CaCO3
-K2CO3
-CaCl2
Calculate the percent yield of CaCO3.
yield of CaCO3= %
Answer:
Limiting reagent is the potassium carbonate.
Percent yield of calcium carbonate is: 39.3 %
Explanation:
The reaction is:
CaCl₂ + K₂CO₃ → CaCO₃ + 2KCl
Formula for percent yield is:
(Produced yield / Thoeretical yield) . 100
Firstly we determine the moles of each reactant, in order to say what is the limiting reagent: ratio is 1:1.
1 mol of chloride need 1 mol of carbonate.
14.570 g . 1 mol /110.98 g = 0.131 moles of CaCl₂
12.285 g . 1 mol / 138.2g = 0.0889 moles of carbonate.
Limiting reagent is carbonate. For 0.131 moles of CaCl₂ we need the same amount of carbonate and we have less moles.
Ratio is also 1:1, with calcium carbonate.
1 mol of potassium carbonate produces 1 mol of calcium carbonate
then, 0.0889 moles will produce the same amount of CaCO₃
We convert moles to mass: 0.0889 mol . 100.08g /mol = 8.89 g
That's the theoretical yield; to find the percent yield:
(3.494 g / 8.89g) . 100 = 39.3%
What is the concentration of s solution that contains 55 mL of alcohol per 145 mL solution?
Answer:
37.9% v/v
Explanation:
Since both the alcohol and solution are presumed to be liquid, this concentration can be expressed as a volume concentration (or % v/v):
volume concentration = volume of solute / volume of solution
[tex]\% v/v = 55/145= 0.379[/tex]
A solution of KMnO4 has an absorbance of 0.539 when measured in the colorimeter. Determine the concentration of the KMnO4 given the following data for a calibration plot.
Concentration of KMNO4 (M) Absorbance
0.0150 0.081
0.0300 0.159
0.0450 0.260
0.0600 0.334
Answer:
Concentration of unknown solution is 0.0416 M
Explanation:
As we know
Absorbance is equal to the product of molar absorptivity of KMnO4 m, path length and concentration
From the given set of graphical data, it is clear that the absorbance vs concentration is a straight line.
From the graph, we can obtain-
Y = 5.73 X – 0.0065
Absorbance = 0.232
0.232 = 5.73 X – 0.0065
X = 0.0416
Concentration of unknown solution is 0.0416 M
The formula for europium oxide is Eu203. On the basis of this information, the formula for the chlorate of europium would be expected to be
Answer:
Eu(ClO3)3
Explanation:
The chlorate ion is written as follows, ClO⁻ ₃. We can see from this that the ion is univalent.
From the formula, Eu203, it is easy to see that the europium ion is trivalent.
Hence, when a compound is formed between the europium ion and chlorate ion, the compound will be written as Eu(ClO3)3.
This is so because, when ionic compounds are formed, there is an exchange of valence between the ions in the compound. This gives the final formula of the ionic substance.
You decide to share some sugar sweetened fruit juice with your friend. You divide the fruit equally into two glasses. Then an additional equal volume of water is added to glass 1. Which glass would have the lower molarity?
Answer:
Glass 1
Explanation:
Molarity is measured in moles of substance per liter.
For the sake of calculations, let's say that each glass contains 1 mole of juice and 1 liter after it is divided between the glasses. If you add an equal amount of water to glass 1 ( another liter), you now have:
Glass 1 = 1 mole / 2 liters = 0.5 M
Glass 1 = 1 mole/ 1 liter = 1 M
So glass 1 will have a lower molarity
At 35°C, K = 1.6 × 10^-5 for the reaction
2 NOCl(g) ⇌ 2 NO(g) + Cl2(g)
Calculate the concentrations of all species at equilibrium for each of the following original mixtures.
a. 2.0 mol pure NOCl in a 2.0 L flask
b. 2.0 mol NOCl and 1.0 mol Cl2 in a 1.0 L flask
Answer:
a) [NOCl] = 0.968 M
[NO] = 0.032M
[Cl²] = 0.016M
b) [NOCl] = 1.992M
[NO] = 0.008 M
[Cl2] = 1.004 M
Explanation:
Step 1: Data given
Temperature = 35°C = 308K
K = 1.6 × 10^-5
Step 2: The reaction
2 NOCl(g) ⇌ 2 NO(g) + Cl2(g)
For 2 moles NOCl we'll have 2 moles NO and 1 mol Cl2
Step 3
a. 2.0 mol pure NOCl in a 2.0 L flask
Concentration at the start:
Concentration = mol / volume
[NOCl] = mol / volume
[NOCl] = 2.0 / 2.0 L
[NOCl] = 1.0 M
[NO] = 0 M
[Cl] = 0M
Concentration at the equillibrium
[NOCl] = 1.0M - 2x
[NO] = 2x
[Cl2]= x
K = [Cl2][NO]² / [NOCl]² = 1.6*10^-5
1.6*10^-5 = ((2x)² * x) / (1.0-2x)²
x = 0.016
[NOCl] = 1.0 - 2*0.016 = 0.968 M
[NO] = 2*0.016 = 0.032M
[Cl²] = 0.016M
b. 2.0 mol NOCl and 1.0 mol Cl2 in a 1.0 L flask
Concentration at the equillibrium
[NOCl] = 2.0 mol / 1.0 L = 2.0 M
[NO] = 0 M
[Cl2]= 1.0 mol / 1.0 L = 1.0 M
Concentration at the equillibrium
[NOCl] = 2.0M - 2x
[NO] = 2x
[Cl2]= 1.0 + x
K = [Cl2][NO]² / [NOCl]² = 1.6*10^-5
1.6 *10^-5 = (2x)²*(1.0+x) / ((2.0-2x)²)
1.6 *10^-5= (2x)² * 1 )/2.0²
1.6 *10^-5= 4x² / 4 = x²
x = [tex]\sqrt{1.6 *10^-5}[/tex] = 4.0*10^-3
[NOCl] = 2.0 - 2*0.004 = 1.992M
[NO] = 2*0.004 = 0.008 M
[Cl2] = 1+ 0.004M = 1.004 M
Complete the following road map for converting volume of A to volume of B for a titration of aqueous solution A with aqueous solution B.
a. multiply by the molarity of B
b. multiply by the moles of B per moles of A
c. divide by the molarity of B
d. multiply by the molarity of A
e. divide by the molarity of A
f. multiply by the moles of A per moles of B
1. volume A (L)
2. moles A
3. moles B
4. volume B (L)
Answer:
Explanation:
The solution of known concentration is expressed as molarity. Molarity is the mole fraction of solute (i.e. the dissolved substance) per liter of the solution, Molarity is also commonly called molar concentration.
Mathematically;
[tex]\mathtt{Molarity = \dfrac{moles \ of \ solute}{ liters \ of \ solution}}[/tex]
To copy and complete the road map from the given question, we have the following array:
Volume A (L)
↓
d. multiplied by the molarity of A
↓
moles A
↓
b. multiplied by the moles of B / moles of A
↓
moles B
↓
c. divided by the molarity of B
↓
volume B (L)
A student named a particular compound 2-ethyl-3-methyl-2-butene. Assuming that the student's choice actually corresponded to the correct distribution of the double bond and the substituents, what is the correct IUPAC name for this compound
Answer:
2-ethyl-3-methylbut-2-ene
Explanation:
The whole idea of IUPAC nomenclature is to devise a universally accepted system of writing the name of a compound from its structure.
According to IUPAC nomenclature, the root of the compound is the longest carbon chain. The substituents are named in alphabetical order and in such a way as to give each one the lowest number. The position of the functional group is indicated accordingly.
For the compound in question, its correct IUPAC name is 2-ethyl-3-methylbut-2-ene.
Using the following equation how many grams of water you would get from 886 g of glucose:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Answer:
531.6g
Explanation:
Total moles of glucose in this case is: 886/180= 4.922 (mole)
For every 1 mole glucose we get 6 mole water
-> Mole of water is: 4.922 * 6= 29.533 (mole)
weight of water is 18. Therefore, total weight of water that we will have from 886g of glucose are: 25.933*18= 531.6g
