From the calculations and the principles of radioactivity, the age of the parent isotope is 144 years
What is radioactivity?The term radioactivity has to do with the spontaneous decay of a substance.
We know that we have about 25% parent isotope still remaining hence;
[tex]0.693/t1/2 =2.303/t log No/N\\When N =0.25 No and t1/2 = 72 years\\0.693/72 =2.303/t log No/0.25No\\0.0096 = 2.303/t *0.60206\\0.0096 = 1.3865/t\\t = 1.3865/0.0096\\t =144 years[/tex]
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Answer:
A. 144 years old
Explanation:
Equal masses of the metals Na, Mg, Ca and Ag are added to separate samples
of excess HCl(aq).
Which metal produces the greatest total volume of H2(g)?
Answer:
The correct answer is Mg
Anyone know the answer to this one?
Answer:
C) 0.24 M
Explanation:
The given chemical reaction is presented as follows;
H₂SO₄(aq) + 2 KOH(aq) → K₂SO₄(aq) + 2 H₂O(l)
The titration experiment results are;
Volume of H₂SO₄(aq) used = 12.0 mL
Volume of KOH (aq) used = 36.0 mL
Concentration of KOH (aq) = 0.16 M
The number of moles of KOH present, n = 0.16 M × 36/1000 = 0.00576 moles
From the given reaction, 1 mole of H₂SO₄ reacts with 2 moles of KOH to give 1 mole of K₂SO₄ and 2 moles of H₂O
Therefore, 0.00576 moles of KOH reacts with (1/2) × 0.00576 moles = 0.00288 moles of H₂SO₄
Therefore, for the reaction;
The number of moles of H₂SO₄ in 12.0 mL of H₂SO₄ = 0.00288 moles
The concentration of the H₂SO₄ = 0.00288 M/(12.0 mL) = 0.24 M
The concentration of H₂SO₄ in the reaction = 0.24 M.
2. Calculate the mass (m) of the hydrated calcium chloride CaCl2.6H20.
Answer:
Explanation:Ca=40
Cl=35.5
cacl2.2h2o=147
2h2o=36
36/147=0.245%
The saturation point for a solution is 45.0 grams of solute per 500 grams of solvent. If you pour 50.0 grams of
solute into 800 grams of solvent, how many grams of solid solute will there be at the bottom of the container?
3-digit answer
Answer:
5.00 g of solute will remain undissolved at the bottom of the container
Explanation:
From the question, the solubility of the solute in the given solvent is 45.0 grams of solute per 500 grams of solvent.
Now if i pour 50.0 grams of solute into 800 grams of solvent, it means that only 45 g will dissolve in 500 g of solvent leaving the additional 5 g undissolved.
Hence, 5 g of solute will remain undissolved at the bottom of the container.
When using a calorimeter, the initial temperature of a metal is 70.4C. The initial temperature of the water is 23.6C. At the end of the experiment, the final equilibrium temperature of the water is 29.8C.
Answer:
temperature of a metal is29.8
temp. of water is 6.2
temp. change of metal -40.6
Explanation:
Carbon dioxide and water are produced when pentane (C5H12) reacts with oxygen. What is the balanced equation for this reaction?
○C5H12(g) + O29) - CO2(g) + H2O(g) ○C5H12(g) + O2(g) - 5CO2(g) + H2O(g)
○C5H12(g) +802(g) - 5CO2(g) + 6H2O(g) ○5CO2(g) + 6H2009) - C5H12(g) + 802(g)
○C5H12(g) +502(g) - 5CO2(g) + 6H2(g)
○CH2(g) +O2(g) + CO2(g) + H2(g)
Answer:
C
Explanation:
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g)
The balanced chemical equation of pentane (C5H12) which reacts with oxygen is
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g)
What is balanced chemical equation?It is the chemical equation in which the atom or molecules or moles of elements on both side reactant and product.
Our reactants are pentane and oxygen. Since, fourth and sixth reaction do not contain pentane. Therefore, fourth and sixth reaction are wrong.
Now, our next step is to compare product.
As we know that, Carbon dioxide and water are produced when pentane (C5H12) reacts with oxygen. So, we get to the conclusion that carbon dioxide and water are the product.
Since, rest of the equation have carbon dioxide and water as product.
On reactant side, there are 5 carbon atoms and 12 hydrogen atom. So, on product side there must be 5 carbon atoms and 12 hydrogen atom. Now we balance the oxygen atom on both side.
Thus, we concluded that the balanced chemical equation of pentane (C5H12) which reacts with oxygen is
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g).
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3.0 mol of NaOH is dissolved in 2.5 L of water, what is the
molarity of the solution?
A. 120 M
B. 40 M
C. 3M
D. 1.2 M
When solution A was mixed with solution B, the solution turned cloudy, the test tube did not feel warm, and there were no visible bubbles. Identify the reaction type.Group of answer choicesprecipitationgas evolvingneutralizationno reactioncombustion
Answer:
Precipitation reaction
Explanation:
Given that solution A was mixed with solution B, the solution turned cloudy. The test is not warm and no bubbles visible. This means that the precipiate is formed.
The concept is when two colourless solutions react to form a cloudy precipitate that settles at bottom of a solution then the reaction is said to be a precipitation reaction.
An example can be the Reaction of Silver nitrate with common salt.
In an exothermic reaction, will increasing or decreasing the reactant cause the reaction to shift towards the product?
thank you :)
Identify which reactants is reduced and which is oxidized .
2Au^3+(aq) + 3Cd(s) -> 2au(s) + 3Cd^2+(s)
Please help
Answer:
CD is oxidised
and
Au is reduced
hope helps u
Please choose a claim and then answer the question below please ty I would appreciate it!
Answer:
Claim 1
Explanation:
I chose this claim because I believe that when the plates under the earth move or shift, that's what causes an earthquake and when everything starts to shake. If it was the other way around there wouldn't be any reason for an earthquake to start.
hope that helped :)
Answer:
Plates move, which can cause earthquakes.
Explanation:
Tectonic plates are always slowly moving, however sometimes they can "lock" together, creating pressure and build up. The release of this energy results in a Tectonic earthquake. Therefore, the movement of plates causes earthquakes.
After a compound X was added to water, the pH using indicator paper was less than 7. The resulting solution was added to some calcium carbonate and it was noted that effervescence took place. What could compound X be?
Answer:
Compound X would be an acid whose pH is below 7 and is able to react with calcium carbonate, a slightly basic salt.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to firstly say that the calcium carbonate is a slightly basic salt, which is likely to react with acids and produce effervescence due to the release of carbon dioxide gas. Moreover, since the compound X exhibited a pH below 7 when dissolved in water, it is 100% sure that this compound is an acid, due to these two reasonings.
Best regards!
An investigation is conducted into how the mass of magnesium metal reacting with hydrochloric acid affects the amount of hydrogen gas produced.
Masses of 0.10g, 0.20g, 0.30g and 0.40g of powdered Mg metal are reacted with hydrochloric acid(HCl). The conical flask containing the reaction mixture of Mg and HCl is connected to another conical flask with a hose. The hydrogen gas produced by the reaction is collected in this conical flask. The greater the amount of hydrogen gas produced by the reaction the greater the pressure of the gas in the flask.
Answer:
A) what is the independent variable:
B) what is the dependent variable:
C) write a hypothesis for this investigation:
D) give 2 variables that should have been controlled for this investigation:
An investigation is conducted into how the mass of magnesium metal reacting with hydrochloric acid affects the amount of hydrogen gas produced.
Masses of 0.10g, 0.20g, 0.30g and 0.40g of powdered Mg metal are reacted with hydrochloric acid(HCl). The conical flask containing the reaction mixture of Mg and HCl is connected to another conical flask with a hose. The hydrogen gas produced by the reaction is collected in this conical flask. The greater the amount of hydrogen gas produced by the reaction the greater the pressure of the gas in the flask.
Answer:
A) what is the independent variable:
B) what is the dependent variable:
C) write a hypothesis for this investigation:
D) give 2 variables that should have been controlled for this investigation:
How many grams of sodium chloride could be produced from 94.3 g of sodium
239.8 g so 240g
Explanation:
plz let me know if this is right than I can tell u how I did it :)
Which of these events is likely to have caused the mass extinction of the dinosaurs?
A.An increase in Earth's overall temperature
B. A large volcanic eruption on nearby islands
C. The fallout of a meteor colliding with Earth's surface
D. Rising sea levels flooding low-lying coastlines
Lower alcohols like methanol burn with a blue flame to form carbon dioxide and water in the presence of atmosphere oxygen. Such a type of reaction is called
A. oxidation
B. combustion
C. dehydration
D. esterfication
Answer:
oxygen
Explanation:
combustion esterfication
Which effects would many organisms likely experience if global warming occurs? Check all that apply.
disrupted food webs
increased competition
increased number of glaciers
disrupted life-cycle events
forced relocation
and any MHA fan to
Answer:
Disrupted food webs
increased competition
disrupted life-cycle events
forced relocation
Explanation:
Global warming refers to a gradual rise in the temperature of the earth due to the increase in the concentration of greenhouse gases in the atmosphere which trap infrared radiation close to the earth.
This gradual increase in the temperature of the earth often have devastating effects on the lives of various organisms on earth. These effects include;
Disrupted food webs
increased competition
disrupted life-cycle events
forced relocation
Due to changes that occur in the ecosystem as a result of global warming, many species may be compelled to relocate from place to place. This in turn disrupts food webs and may lead to disruption of life cycle events of the concerned organisms. Decrease in the number of certain populations due to global warming may lead to increased competition among species for food.
PLZ HELP!!! WILL GIVE BRAINLIEST!! Balance the following equations to show the law of conservation of mass: (10 points - 1 point for each correct line)
if a half life is 2.5 hours, how long is 2 half life's
Answer:
Im not really sure what a half life is, but two of them would be 5.0 hours
Answer:
5 hours
Explanation:
cause if half life is 2.5hours we just multiply it by two and get 5 hours
An electromagnetic wave has a wavelength of 4000 meters. What is this wave length and scientific notation?
A. 4.0 x 10-3 m
B. 4.0 x 10 3 m
C. 4.0 x 10 2 m
D. 4.0 x 10-2 m
Answer:
Wavelength of electromagnetic wave = 4.0 × 10³
Explanation:
Given:
Wavelength of electromagnetic wave = 4000 meter
Find:
Write, Wavelength of electromagnetic wave into scientific notation
Computation:
Wavelength of electromagnetic wave = 4000 meter
Wavelength of electromagnetic wave = 4.0 × 1,000 meter
Wavelength of electromagnetic wave = 4.0 × 10³
So,
Option "B" is the correct answer to the following question.
Names for following compounds.
a)CO²
b)NaCI
c)S²CI²
d)NaF
Can the excess reactant control the percentage yield
Explanation:
when one reactants is in excess, there will always be some left over. The other reactants becomes limiting factor and controls show much of each product is produced.while using excess percentage yields this is at the expense of atom economy.
Use the reaction shown l to answer these questions.
2CO(g) + 2NO) → N2(g) + 2CO2(g)
If 42.7 g of CO is reacted completely at STP, what
volume of N2 gas will be produced?
Answer:
16.8dm3
Explanation:
2 moles of CO gives 1 mole of N2
2 moles of CO= 2* 28= 56g
1 mole of N2 = 1* 22.4dm
56g of CO gives 22.4dm3 of N2
42.7 of CO will give> (42.7*22.4)/56
=16.8dm3
The volume of [tex]N_{2}[/tex] gas will be produced 16.8 [tex]dm^{3}[/tex].
What is volumeVolume is sometimes referred to as capacity. The volume of a cylindrical jar, for example, is used to determine how much water it can hold.
Calculation of volume is shown below:
The given reaction is: 2CO(g) + 2NO) → N2(g) + 2CO2(g)
It can be seen that 2 moles of CO give 1 mole of [tex]N_{2}[/tex].
So, 2 moles of CO = 2×28 = 56 g.
Hence, 1 mole of [tex]N_{2}[/tex] = 1×22.4 = 22.4 [tex]dm^{3}[/tex].
56 g of CO will give 22.4 [tex]dm^{3}[/tex] of nitrogen atom.
42.7 of CO will give = (42.7×22.4) / 56
= 16.8 [tex]dm^{3}[/tex].
Therefore, the volume of nitrogen will be 16.8 [tex]dm^{3}[/tex].
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Calculate the mass of water produced when 25.0g of oxygen gas react with
42.0g of hydrogen gas.
2H2 + O2 -> 2H,0
Reaction.-
2H2 + O2 ---> 2H2O
Given,
Mass of Oxygen - 25.0 g
Mass of Hydrogen - 42.0 g
now we have to calculate moles
moles of O2 = 25/16 = 1.5625 moles
Moles of H2 = 42/2 = 21 moles
Hydrogen gas is in excess,
now using reaction
1 mole of oxygen gas forms 2 moles of H2O
1.5625 mole of Oxygen gas will form x mole of H20
x = 3.125 moles
molar mass of H2O is 18g
mass of 3.125moles of water = 3.125 × 18 = 56.25 g.
Hence the mass of water produced when 25.0g of oxygen gas react with 42.0g of hydrogen gas is 56.25 grams
2. How did the Activator affect the mixture?
Answer:
Activator effects a mixture if you put to much of the activator your using into a product or thing you are using.
Explanation:
For ex.
If you poor to much activator into slime it will make the slime hard and very wet it will ruin your slime completely so you will have to do it just right but start off pouring it slowly and mix and then more if it needs more.
The gas left in a hairspray can is at a pressure of 121.2kPa at 25.0°C. If this can is thrown into a fire, what will be the resulting pressure if the fire reaches 2,111°C
Answer:
969.6 kPa
Explanation:
Applying,
P/T = P'/T'..................... Equation 1
Where P = Initial pressure of the gas, T = Initial temperature of the gas, P' = Final pressure of the gas, T' = Final temperature of the gas
make P' the subject of the equation
P' = PT'/T................. Equation 2
From the question,
Given: P = 121.2 kPa, T' = 2111°C = (273+2111) = 2384 K, T = 25°C = (273+25) K = 298 K
Substitute these values into equation 2
P' = (121.2×2384)298
P' = 969.6 kPa
Helpppp i need da right answer Don’t Guess
Answer:
2.8 kg = 2.8 x 10^6 mg
Explanation:
Multiply the value in kilograms by the conversion factor (1000000) otherwise known as 10^6
So, 2.8 kilograms = 2.8 x 1000000 = 2.8 x 10^6 or 2800000 miligrams
balance NaHCO3(S) -NaOH(S)+CO(G)
Answer:
NaHCO3(s) → NaOH(s) + CO2(g)
Explanation:
A balanced chemical equation is that in which the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side.
Based on the following equation below, each atom on the reactant side matches the ones on the product side, hence, the equation is said to be balanced. The balanced equation is as follows:
NaHCO3(s) → NaOH(s) + CO2(g)
What is the molar it's of a solution that has 0.080 moles of calcium chloride dissolved in 850mL of solution.
Answer:
The molarity of the solution is 0.094 [tex]\frac{moles}{liter}[/tex]
Explanation:
Molarity is a measure of the concentration of that substance and is defined as the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units[tex]\frac{moles}{liter}[/tex].
In this case:
number of moles of solute: 0.080 molesvolume= 850 mL= 0.850 LReplacing:
[tex]Molarity=\frac{0.080 moles}{0.850 L}[/tex]
Solving:
Molarity= 0.094 [tex]\frac{moles}{liter}[/tex]
The molarity of the solution is 0.094 [tex]\frac{moles}{liter}[/tex]
Which of the following coefficients will correctly
balance the equation below?
H20
CH4+ ___ O2 --> CO2+ _H2O
1) 3,3
2) 2,2
3) 2,3
4) 1,2
Answer:
#2 is the answer
Bcuz 2 times 2 = 4