Answer:
I think third C12/hv is right answer
Compared to an atom of C-12, an atom of C-14 has
A) fewer protons
C) more neutrons
B) fewer neutrons
D) more protons
Explanation:
Carbon-12 atoms have stable nuclei because of the 1:1 ratio of protons and neutrons.
Carbon-14 atoms have nuclei which are unstable. C-14 atoms will undergo alpha decay and produce atoms of N-14. Carbon-14 dating can be used to determine the age of artifacts which are not more than 50,000 years old.
According to an informal 1992 survey, the drinking water in about one-third of the homes in Chicago had lead levels of about 10 ppb. Dr. Koether lived in Chicago from 1996 to 1998. Assuming she drank 1.4 L of water a day, calculate the total amount of lead in mg (using one decimal place) that she was exposed to over the two years if she lived in a home that had such high levels of lead.
Answer:
10.2 mg
Explanation:
Step 1: Calculate the total amount of water she drank
1 year has 365 days and she lived in Chicago for 2 years = 2 × 365 days = 730 days.
If she drank 1.4 L of water per day, the total amount of water she drank is:
730 day × 1.4 L/day = 1022 L
Step 2: Calculate the amount of Pb in 1022 L of water
The concentration of Pb is 10 ppb (10 μg/L).
1022 L × 10 μg/L = 10220 μg
Step 3: Convert 10220 μg to milligrams
We will use the conversion factor 1 mg = 1000 μg.
10220 μg × 1 mg/1000 μg = 10.2 mg
Predict whether solutions of each of the following salts will be acidic, basic, or neutral. Explain your reasoning for each by writing a balanced net ionic equation to describe the chemistry of each non-neutral salt in water:
a. NaCN
b. KNO3
c. NH4Cl
d. NaHCO3
e. Na3PO4.
Answer:
NaCN- basic salt
KNO3 - neutral salt
NH4Cl - acid salt
NaHCO3 - acid salt
Na3PO4 - acid salt
Explanation:
Salt hydrolysis a process by which salts react with water giving an acid and a base.
When we dissolve NaCN in water, we have;
NaCN + - ⇄ Na^+ + CN^-
KNO3 ------> K^+ + NO3^-
NH4Cl ------> NH4^+ + Cl^-
NaHCO3 -----> Na^+ + HCO3^-
Na3PO4 ----> 3Na^+ + PO4^3-
Note that if a salt is formed from a weak acid and a strong base, the salt will be a basic salt e.g NaCN formed from weak HCN and strong NaOH.
If a salt is formed from a strong acid and weak base, the salt will be acidic, e.gNH4Cl formed from weak NH3 and strong HCl.
If a salt is formed from a strong acid and strong base, the salt will be neutral, e.g KNO3 formed from strong KOH and strong HNO3.
Which of the following is an example of a scientific theory?
Matter can be neither created nor destroyed.
Force equals mass times acceleration.
Matter behaves the way it does because it is made of atoms.
There is probably life on Mars.
C. Matter behaves the way it does because it is made of atoms.
Answer:
Matter can neither be created nor destroyed
Explanation:
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An analytical chemist is titrating of a solution of hydrazoic acid with a solution of . The of hydrazoic acid is . Calculate the pH of the acid solution after the chemist has added of the solution to it.
Answer:
pH = 12.43
Explanation:
...is titrating 212.7 mL of a 0.6800 M solution of hydrazoic acid (HN3) with a 0.2900 M solution of KOH. The p Ka of hydrazoic acid is 4.72. Calculate the pH of the acid solution after the chemist has added 571.6 mL of the KOH solution to it.
To solve this question we need to know that hidrazoic acid reacts with KOH as follows:
HN3 + KOH → KN3 + H2O
Moles KOH:
0.5716L * (0.2900mol /L) =0.1658 moles of KOH
Moles HN3:
0.2127L * (0.6800mol/L) = 0.1446 moles HN3
As the reaction is 1:1, the KOH is in excess. The moles in excess of KOH are:
0.1658 moles - 0.1446 moles =
0.0212 mol KOH
In 212.7mL + 571.6mL = 784.3mL = 0.7843L
The molarity of KOH = [OH-] is:
0.0212 mol KOH / 0.7843L = 0.027M = [OH-]
The pOH is defined as -log [OH-]
pOH = -log 0.027M
pOH = 1.57
pH = 14 - pOH
pH = 12.43
A 1 L container originally holds 0.4 mol of N2, 0.1 mol of O2, and 0.08 mole of NO. If the volume of the container holding the equilibrium mixture of N2, O2, and NO is decreased to 0.5 L without changing the quantities of the gases present, how will their concentrations change
Answer:
a) [tex]N_2=0.8mol/L[/tex]
b) [tex]O_2=0.2mol/L[/tex]
c) [tex]NO=0.16mol/L[/tex]
Explanation:
From the question we are told that:
Moles 0f Nitrogen [tex]N_2=0.4[/tex]
Moles 0f Oxygen [tex]O_2=0.1[/tex]
Volume Decrease [tex]V_2=0.5L[/tex]
Generally, the equation for Concentration is mathematically given by
[tex]C=\frac{moles}{V}[/tex]
For Nitrogen
[tex]N_2=\frac{0.4}{0.5}[/tex]
[tex]N_2=0.8mol/L[/tex]
For Oxygen
[tex]O_2=\frac{0.1}{0.5}[/tex]
[tex]O_2=0.2mol/L[/tex]
For Nitrogen
[tex]NO=\frac{0.08}{0.5}[/tex]
[tex]NO=0.16mol/L[/tex]
11. How many oxygen atoms are there in one formula unit of Ca2+?
Answer:
NO3 has 3 atoms of oxygen in it per molecule (indicated by the subscript of 3) and (NO3)2 means you have 2 NO3 molecules, meaning you double the subscript to get 6 oxygen atoms.
Explanation:
An object with a mass of 3kg has a force of 9 newtons applied to it. What
is the resulting acceleration of the object?
Answer:
3 m/s^2
Explanation:
m = 3 kg
F = 9 N
Use Newton's Second Law: F = ma
9 = 3a
a = 3 m/s^2
Explain why it is not advisable to add water to acid when
mixing them
Answer:
Consequence
you form an extremely concentrated solution of acid initially.and the solution may boil very violently, splashing concentrated acid. I hope this helped! :)In water, a substance that ionizes completely in solution is called a
Answer:
please mark me brainliest
Explanation:
In water, a substance that ionizes completely in solution is called a weak electrolyte.
Answer: strong electrolyte.
Explanation: In water, a substance that ionizes completely in solution is called a. a. weak electrolyte.
The correct geometry around oxygen in CH3OCH3 is
(a). linear. (b). bent. C). tetrahedral/(a). trigonal planar
Explanation:
the force of the lone pairs from the bottom would cancel out the force of the lone pairs from the top. Thus, the molecule will be linear.
A functional group introduces heteroatoms into a carbon chain to increase
polarity.
chain length.
molecular mass.
reactivity.
Answer:
reactivaty
Explanation:
here you go for the answer
Over a long period of time the process of deposition causes the formation of
O
A. acid rain
OB. glaciers
OC. sedimentary rock
OD. Karst topography
Answer:
C. sedimentary rock
Explanation:
Deposition is basically a process in which sediments are added to land.
What is the purpose of the periotic table?
Answer:
The periodic table was first designed by Mendeleev. It is designed to systematically categorise elements according to atomic number, electron configuration and recurring chemical properties. This allows identification of elements through their characteristics simply by analysing its position on the table.
Which of the following stays constant when diluting a solution?
Select the correct answer below:
A) volume
B) molarity
C) concentration
D) amount of solute
Answer:
when you're diluting a solution, you're adding in more solvent, so the solute will maintain the same (D)
When a chemical changes from the solid phase to the gas phase, this is an example of What chemical property?
Answer:
sublimation
Explanation:
solid => liquid Melting
liquid => solid freezing
liquid => gas evaporation
gas => liquid condensation
solid => gas sublimation
gas => solid deposition (e.g.; formation of frost), however some scholars will also refer to this process as sublimation.
Which molecule is butane?
Answer:
option c see image... and yw
The molecule shown in option C is butane.
What is butane?The organic compound with four carbon atoms and ten hydrogen atom lie in linear chain without any functional group is called butane.It is belongs to alkane family.What is alkane?It is acyclic saturated hydrocarbons organic compounds.It is also known as paraffin.An alkanes contain carbon atoms and hydrogen atoms bonded with single bond.It general formula is [tex]C_{n} H_{n+2}[/tex] .To learn more about butane,
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HELP ASAP PLS
Reactions, products and leftovers
Answer:
See the answer below
Explanation:
From the original equation in the image, the mole ratio of C:CO2:CO is 1:1:2. This means that for every 1 mole of C and CO2, 2 moles of CO would be produced.
Now, looking at the simulation below the equation of the reaction, 3 moles of C and 8 moles of CO2 were supplied as input. Applying this to the original equation of reaction, C seems to be a limiting reagent for the reaction because the ratio of C to CO2 should 1:1.
Hence, taking all the 3 moles of C available means that only 3 moles out of the available 8 for CO2 would be needed. 3 moles c and 3 moles CO2 means that 6 moles CO would be produced (remember that the ratio remains 1:1:3 for C, CO2, and CO). This means that 5 moles CO2 would be leftover.
In other words, all the 3 moles C would be consumed, 3 out of 8 moles CO2 would be consumed, and 6 moles CO would be produced while 5 moles CO2 would be leftover.
What is the balanced equation for the reaction of lithium metal with fluorine gas? Li ( s ) + F ( g ) → LiF ( s ) Li ( s ) + F 2 ( g ) → LiF ( s ) 2 Li ( s ) + F 2 ( g ) → 2 LiF ( s ) Li ( s ) + F 2 ( g ) → LiF
Answer:
2Li(s) + F2(g)→2LiF(s)
Explanation:
a team of engineers has decided to design a new shoe for people suffering from a painful foot condition. What should the engineers do during the planning stage
team of engineers has decided to design a new shoe for people suffering from a painful foot condition. What should the engineers do during the planning stage
Congratulations! You are now the head biologist at the local "Cells and Bells" research lab! It has come to other cell biologists' attention recently that some cells are too small to contain all of the organelles inside of them. They decide that it's best to get rid of an organelle, but they're not sure which one. In the first process of this decision, they need to know "which organelle is the most important?"
Your job, as the head cell biologist, is to decide which organelle the cell cannot live without.
Write a research paper (intro, body, and conclusion) on which organelle is the most important and why.
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A mixture of copper sulfate and water is heated, leaving a residue of copper sulfate in the container. Which method was used to separate the mixture?
A. chromatography
B. evaporation
C. filtration
D. distillation
The method used to separate copper sulfate and water mixture was evaporation.
Explanation:
Chromatography is a separation technique used in labs. In this technique, there are two phases, the mobile phase, and the stationary phase. The phase in which the mixture is dissolved is termed as mobile phase and the phase which serves as a carrier through the system like, sheet, capillary, etc. is termed as mobile phase.Evaporation is a process in which the action of heat is employed to separate dissolved solids from liquid. Due to heat liquid gets evaporated leaving the solid behind.Filtration is a process in which insoluble particles are separated from the liquid by allowing them to pass through a porous substance such as filter paper. Distillation is a process used in the separation of the mixture of liquids with different boiling points.So, from this, we can conclude that the method used to separate copper sulfate and water mixture was evaporation.
Learn more about separation techniques here
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Answer:
Just did this on my test the answer is evaportion.
Explanation:
What is the mass of 7.2 moles of titanium to the nearest tenth?
Answer:
7.2 moles of titanium weigh 344.7 grams.
Explanation:
Molar mass of titanium = 47.88 g
[tex]1 \: mole \: of \: titanium = 47.88 \: grams \\ 7.2 \: moles \: of \: titanium = g[/tex]
solve for g
[tex]g = ( \frac{7.2 \times 47.88}{1} ) \\ g = 344.7 \: grams[/tex]
Answer:
[tex]\boxed {\boxed {\sf 344.7 \ g \ Ti}}[/tex]
Explanation:
We are asked to find the mass of 7.2 moles of titanium.
To convert from moles to grams, we use the molar mass. This value is the mass of 1 mole of a substance. They are equivalent to the atomic masses found on the Periodic Table, but the units are grams per moles instead of atomic mass units.
Look up titanium's molar mass on the Periodic Table.
Ti: 47.87 g/molConvert moles to grams using dimensional analysis. First, set up a ratio using the molar mass.
[tex]\frac {47.87 \ g \ Ti}{1 \ mol \ Ti}[/tex]
We are converting 7.2 moles to grams, so we multiply the ratio by this value.
[tex]7.2 \ mol \ Ti *\frac {47.87 \ g \ Ti}{1 \ mol \ Ti}[/tex]
The units of moles of titanium cancel.
[tex]7.2 *\frac {47.87 \ g \ Ti}{1 }[/tex]
The denominator of 1 can be ignored (a number over 1 is just the number).
[tex]7.2 *47.87 \ g \ Ti}[/tex]
[tex]344.664 \ g \ Ti[/tex]
We are asked to round to the nearest tenth. The 6 in the hundredth place tells us to round the 6 in the tenth place up to a 7.
[tex]344.7 \ g \ Ti[/tex]
There are approximately 344.7 grams of titanium in 7.2 moles of titanium.
The valves in the heart open and close to move blood in between heart chambers. O a) three directions O b) two directions O c) four directions d) one direction
Answer:
im not sure but i think its four directions
Hi,
The valves in the heart open and close to move blood in between heart chambers.
Answer:
d) one direction
What particules make up the nucleus
Answer:
nucleus is a collection of particles called protons,which are positively charged..and neutrons which are electrically neutral..electrons which are negatively charged..and neutrons are in turn made up of particles called quarks ..
Explanation:
hope this helps u ...
Answer:
The Nucleus is made up of protons and neutrons.
Rewrite this measurement with a simpler unit, if possible.
4.5·m2m2m
Answer:
why are people s opinions and prejudices her greatest obstacles
Wet helium gas is placed into a balloon at 24.4 degrees Celsius and a pressure of 765.3 mm Hg. What volume (in L) does the dry gas occupy if the water vapor pressure is 24.3 torr and the mass of dried helium gas in the balloon is 0.498 g
Answer:
Hence the Volume of Gas = 3.04 L.
Explanation:
pressure of dry gas = 765.3 - 24.3 = 741 mmhg
Temperature of gas = 24.4+273.15 = 297.55 k
No of mol of gas = 0.498/4 = 0.1245 mol
R = gas constant = 0.0821 l.atm.k-1.mol-1
From ideal-gas equation
PV = nRT
(741/760) x v = 0.1245 x 0.0821 x 297.55
V = Volume of Gas = 3.04 L
A water chemist measured and recorded the air temperature at 27°C when he should have measured the water temperature, which was only 21°C. As a result of this error, will the dissolved oxygen concentration be reported as being higher or lower than it should be? Explain.
Answer:
See explanation
Explanation:
The dissolution of oxygen in water is exothermic. Hence, at higher temperature, less oxygen is dissolved in water.
If the chemist commits an error and records 27°C instead of 21°C, the dissolved oxygen concentration will be found to be lower than it should be at 27°C because dissolution of gases in water is exothermic.
pls help!!! How can you prove the pennies are made of different material aside from cutting them in half?
Answer:
Most of our coins are metal sandwiches. The outside layers are three-quarters copper and one-quarter nickel, and the "filling" is solid copper. Pennies are made of zinc coated with copper. Only nickels are one solid material—that same 75% copper/25% nickel alloy
Explanation:
How do the particles in plasmas compare with
the particles in solids?
O Plasmas and solids are both made up of cation-anion pairs.
• Solids and plasmas are both made up of electrons and cations.
Solids are made up of cation-anion pairs, but plasmas are not.
O Plasmas are made up of cation-anion pairs, but solids are not.
Answer:
Solids are made up of cation-anion pairs, but plasmas are not
Explanation:
Solid is made from cautions and anions while the plasma is not and hence both are made from the cautions and anion plasma. Solids and plasma is made from electrons and solids are made from caution and anion pairs. Plasma is a good conductor of electricity as they have a lot of mobile charged particles.