Explanation:
From the question given above, the following data were obtained:
Half-life (t½) = 9.7 days
Time (t) = 60 days
Percentage remaining after 60 days =?Next, we shall determine the number of half-lives that has elapsed. This can be obtained as follow:
Half-life (t½) = 9.7 days
Time (t) = 60 days
Number of half-lives (n) =?
n = t / t½
n = 60 / 9.7Finally, we shall determine the percentage remaining. This can be obtained as follow:
Let the original amount be N₀
Let the amount remaining be N
Number of half-lives (n) = 60 / 9.7
N = N₀ / 2ⁿ
Divide both side by N₀
N/N₀ = 1/2ⁿ
N/N₀ = 1 / 2⁽⁶⁰÷⁹•⁷⁾
N/N₀ = 0.0137
Multiply by 100 to express in percentage
N/N₀ = 0.0137 × 100
N/N₀ = 1.37%Therefore, the percentage remaining after 60 days is 1.37%
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when a 2.71 mL sample of a 0.493 M aqueous nitrous acid solution is tutorage with a 0.308 M aqueous sodium hydroxide solution, what is the ph after 65.1 mL of sodium hydroxide have been added?
Answer:
0.10 M NaHA
Explanation:
If 9 moles of P203 are formed, how many
moles of O2 reacted?
Please choose and answer 3 of the following 4 questions:
1. Rutherford and JJ Thompson both contributed to what we know about the structure of the atom. What experiments did they perform and how did it change what we know about the structure of the
atom? Furthermore, describe the structure of an atom using only words (no diagrams).
2. Electrons exist outside the nucleus on many different energy levels. When electrons lose energy, they emit waves that are found on the electromagnetic spectrum. What equation would you use to
find the wavelength or frequency of a wave, assuming you know the other value? What is the relationship between frequency and wavelength? What is the relationship between frequency and
energy?
3. Even though electrons move around constantly, scientists use electron configurations to give an "address" to a particular electron. What are the 4 shells that scientists use? How many electrons can
fit into each shell? How can you use the knowledge about these shells and the periodic table to determine the electron configuration of an element?
4. Suppose you know there is an element with an atomic number of 26 and a mass of 60. What do you know about this element? How many subatomic particles does it have? How can you tell?
Answer:
1. Rutherford performs the gold foil experiment while JJ Thompson performs cathode ray experiment. It was Rutherford's experiment that used positively charged alpha particles (He with a +2 charge) that were deflected by the dense inner mass of the nucleus (nucleus). The conclusion that could be drawn from this finding was that atoms were composed of an inner core that comprised the majority of the atom's mass and was positively charged in nature. The work of JJ Thompson using cathode ray tubes demonstrated that all atoms contain small negatively charged subatomic particles, also known as electrons. According to Thomson's conception of the atom, which had negatively-charged electrons buried inside a positively-charged "soup," the atom was made of plum pudding. Protons, electrons, and neutrons are the three fundamental particles that make up an atom. The protons (which are positively charged) and neutrons (which are neutrally charged) are found in the nucleus (center) of an atom (no charge). The electrons are contained inside the electron shells, which are the outermost parts of the atom (negatively charged).
2. Given that the frequency is 1/T, the equation linking wave speed, frequency, and wavelength is v=f t. The relationship between frequency and wavelength is inversely proportional. The wavelength of the wave with the highest frequency is also the shortest. When the frequency is doubled, the wavelength is cut in half. As a result, the wavelength to frequency ratio is the inverse of the frequency to wavelength ratio. When it comes to carrying energy, the frequency and amplitude of the waves are important factors to consider. The higher the frequency, the greater the amount of energy, and the larger the amplitude, the greater the amount of energy.
3. There are four shells that scientists used. First shell contains 2 electrons. Second shell consists of 8 electrons. Third shell has 18 electrons. Lastly, fourth shell has 32 electrons. 2 electrons can fit into each shell. If you want to compute an electron configuration, first split the periodic table into portions that represent the atomic orbitals, which are the locations where electrons are found. The s-block is represented by groups one and two, the d-block by groups three through twelve, the p-block by groups thirteen through eighteen, and the f-block by the two rows at the bottom.
Explanation:
That's the three questions I chose to answer. Hope it helps;)
If the vapor pressure of water at 20.0 o C is 17.535 torr, and the atmospheric pressure measured by a barometer was 757.3 torr, what is the partial pressure of H2 in the gas mixture in a buret
Answer:
f the vapor pressure of water at 20.0 o C is 17.535 torr, and the atmospheric pressure measured by a barometer was 757.3 torr, what is the partial pressure of H2 in the gas mixture
Partial pressure of H2 in gas mixture is :
739.765 torr .
Explain total pressure?The overall pressure ptot is the total of all pressures in a reference system. This pressure, according to Bernoulli (see Fluid mechanics), consists of the static pressure p, the dynamic pressure pdyn, and the geodetic component ( g z) that exists in a fluid along a stream line in a frictionless flow.The total pressure of a gas mixture is the sum of its component gases' partial pressures: Ptot = ∑Pi = P1 + P2 + P3... ntot = total number of moles in the gas mixture (the sum of all ni).Total pressure of mixture =
Partial of hydrogen + Partial pressure of oxygen
Partial of Hydrogen = Total pressure - partial pressure of oxygen
Here total pressure = 757.3 torr
Partial pressure of oxygen = 17 . 535 torr
Total pressure = 757 . 3 - 17 . 533
= 739.765 torr.
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The model below shows the equation that represents how hydrogen and oxygen combine to form water. In this chemical reaction, the reactants
are hydrogen gas and oxygen gas.
2H2 + O2 + 2H2O
True
False
Answer:
true
Explanation:
because they are balance
What is important about the properties of a substance that has undergone a chemical
change?
The substances created during chemical reactions, on the other hand, do not simply revert to their initial state. The most essential thing to remember is that the makeup of a material does not change when it undergoes a physical change, but it does change when it undergoes a chemical change.
Answer:
the most important thing for you to remember is that in a physical change composition of a substance does not change and in a chemical change the composition of a substance does change
Which functional group does the molecule below have?
Answer:
B
Explanation:
We can see here that the functional group that the molecule have is: B. Carbonyl
What is a functional group?A functional group is a specific group of atoms or bonds within a molecule that is responsible for the characteristic chemical reactions and properties of that molecule. Functional groups are the parts of organic molecules that determine their reactivity and the types of chemical reactions they can undergo.
In organic chemistry, functional groups play a crucial role in understanding the structure and behavior of molecules. Different functional groups confer distinct properties to molecules, influencing their physical properties, solubility, acidity or basicity, and interactions with other molecules.
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Can someone please help. I have no idea how to do this
Explanation:
c-o number if electrons shared: 4. doubke bond. non polar
c-cl 2 electrons sharde single bond non polar
I know this cause one dash equals 2 electrons chemistry teachers use them when two compounds are sharing electrons rather then using two dots so people know the difference
What is the percentage of nitrogen in ammonium chloride (NH4Cl)?
Answer:
25%
Explanation:
Ammonium Chloride NH4CI Fertilizer-grade NH4Cl usually contains 25% N. About two-thirds of the world capacity for manufacture of this material is located in Japan, with the remaining one-third situated in India and China.
Which example accurately describes a solution? (1 point)
Nonpolar oil molecules dissolve in water, which is polar.
Polar sugar molecules dissolve in water, which is polar.
Nonpolar fat molecules dissolve in water, which is polar.
Polar sugar molecules dissolve in oil, which is nonpolar.
The example which accurately describes a solution is; Polar sugar molecules dissolve in water, which is polar.
According to the question:
We are required to determine Which example accurately describes a solution.The formation of a solution requires that the solvent and solute be of the same polarity.
In essence, the example which accurately describes a solution is; Polar sugar molecules dissolve in water, which is polar.
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Answer:
Polar sugar molecules dissolve in water, which is polar.
Explanation:
I did the Exam and got it right!
milk is heterogeneous mixture why
Answer:
Milk is essentially a colloidal dispersion of fat in water. ... However, the fact remains that the fat and water components cannot be mixed together from a solution. There are therefore, two distinct immiscible liquid phase's present, which is why it is a heterogeneous mixture.
Complete the balanced dissociation equation Cs2CO3
The balanced dissociation equation for Cs₂CO₃ is:
Cs₂CO₃(aq) —> Cs⁺(aq) + CO₃²¯(aq)
A dissociation equation is an equation showing the available ions present in a solution.
To obtain the dissociation equation, the compound must be dissolved in water to produce an aqueous solution.
The dissociation equation for Cs₂CO₃ can be written as follow
Cs₂CO₃(aq) —> Cs⁺(aq) + CO₃²¯(aq)
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What is the molarity of the nitric acid solution if 20.5 mL of a 0.125 M lithium hydroxide solution are needed to titrate a 25.0 mL sample of the nitric acid solution
Answer:: We're asked to find the molar concentration of the NaCl solution given some titration data.
Explanation:
If 0.45 mole oxygen gas occupies a volume of 1.5 L, what volumes will 2.0 moles of oxygen gas occupy at the same temperature and pressure?
please don't send YouT8ube link i need a solution
Answer:
1. How many moles of oxygen will occupy a volume of 2.5 liters at 1.2 atm and 25° C? PV = V (1.2 n. 0821) (298) = 123 mols 2.
2.0 moles of oxygen gas will occupy a volume of 6.67 L at the same temperature and pressure.
Moles is a unit of measurement used in chemistry to express the amount of a substance. It is a counting unit that represents the number of particles, such as atoms, molecules, or ions, in a given sample.
One mole of a substance is defined as the amount of that substance that contains Avogadro's number of particles, which is approximately 6.022 x 10²³. This number is based on the concept that atoms, molecules, and ions are extremely small and difficult to count individually, so using moles allows for a more practical and convenient representation of quantities.
Given:
Moles of oxygen gas (initial) = 0.45 mol
Volume of oxygen gas (initial) = 1.5 L
Moles of oxygen gas (final) = 2.0 mol
Volume of oxygen gas (final) = ?
Using the principle of molar volume, we can set up the following ratio:
(0.45 mol / 1.5 L) = (2.0 mol / V)
V = (1.5 L × 2.0 mol) / 0.45 mol
V = 6.67 L
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When 2.0 mol of methanol is dissolved in 45 grams of water, what is the mole fraction of methanol
The mole fraction of methanol in the mixture is 0.444
We'll begin by calculating the number of mole of water.
Mass of water = 45 gMolar mass of water = 18 g/molMole of water =?Mole = mass / molar mass
Mole of water = 45 / 18
Mole of water = 2.5 moles
Finally, we shall determine the mole fraction of methanol.
Mole of water = 2.5 molesMole of methanol = 2 molesTotal mole = 2 + 2.5 = 4.5 molesMole fraction of methanol =?
Mole fraction = mole / total mole
Mole fraction of methanol = 2 / 4.5
Mole fraction of methanol = 0.444
Thus, the mole fraction of methanol is 0.444
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1 point
Convert 3.79 x 10^24 atoms of sodium to grams.
Answer:
is easy to poiling
Explanation:
also is dificult to melting
Which type of molecule is propanol?
A. Alcohol
B. Aldehyde
C. Ketone
D. Amine
Answer:
A
Explanation:
Alcohol is a type of molecule in propanol. Hence, option A is correct.
What is propanol?Propanol molecular formula is C₃H₇OH.
C₃H₇OH contains -OH functional group which belongs to alcohol.
Hence, option A is correct.
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What are the two elements sand is made of? *
Answer:
tiny crystals of the mineral quartz, which is made out of silica and oxygen
Well, much of the world's sand is made out of the same stuff, tiny crystals of the mineral quartz, which is made out of silica and oxygen, the two most common elements in Earth's crust.
A baker was baking a cake which has burnt due to over heating. What kind of change is this ?
reversible
irreversible
burnt
heating
LAST ATTEMPT! Covalent compound naming !
S2Cl4 = Disulfur Tetrachloride
C5Br8 = N/A
Cl2O3 = Dichlorine trioxide
H2S3 = Trisulfane
Formula: N4S4 = Trisulfur Tetrafluoride
Formula: CBr4 = Hexanitrogen trisulfide
Formula: SiO2 = Heptasilicon
Carry learning!
Stay safe!
Study hard!
Which pair of elements form an ionic bond with
each other?
A. KCL
B. ICL
C. PCL
D. HCL
I think it’s A and D but if it’s not both can you please explain why it’s one and not the other?
Answer:
Yes Both A) KCL and D) HCL are correct...
Answer:
It's only A
Explanation:
Potassium (K) is a metal and Chlorine (Cl) is a nonmetal, and ionic compounds are formed between metals and nonmetals. So KCl forms ionic bonds.
Hydrogen (H) and Chlorine (Cl) are both nonmetals, and only covalent bonds form between nonmetals. (Only exception is when its an acid, then it's ionic)
Also, the question indicated which "pair" and not "pairs" meaning that there is only one answer, and I'm more likely to go with A rather than D.
6. The valence number of a metallic element x is 3. What is the chemical formula of its B. Nitride?
Electrical bonding refunding quick check!!
A team wants to understand the effects of molecular weight on boiling point. The team has access to five substances with
different molecular weights and the time to measure 50 boiling points. How can the team make the best use of the laboratory
testing time? (1 point)
O by taking 10 measurements of each of the five liquids and using the highest value from each set
O by taking 10 measurements of each of the five liquids and finding an average
O by taking measurements of the liquids one at a time, making sure that the correct results are achieved before
moving on to another liquid
O by taking one measurement of each liquid and then working to improve the least certain liquid in the group
Answer:
1. More data should be collected to get a more reliable average
2. A boiling point at 1.5 atmospheres could be predicted fairly well
3. The actual boiling point is probably between 34 C and 40 C
4. By taking 10 measurements of each of the five liquids and finding an average
5. The thermometer being used might need to be recalibrated
Explanation:
Took the quick check
K3PO4(aq)+MgCl2(aq)⟶
Answer:
6KCl(aq) + Mg3(PO4)2(s) ... balanced equation
Explanation:
A 0.1 M NaCl solution and a 0.2 M glucose solution are separated by a membrane that is impermeable to these solutes but is permeable to water. What will happen
nothing will happen
if you calculate the water potiential for both solutions
you get 2(0.1)(R)(T) and 1(0.2)(R)(T)
which is the same thing, so its isotonic.
Acid hydrolysis of N-methylbutyramide in water and hydrochloric acid with heat produces______________________________.
a. Butyric acid and methylammonium chloride.
b. Butanoic acid and ammonium chloride.
c. Butanoate and methylamine.
Answer:
A- Butyric acid and methylammonium chloride.
Explanation:
Octane has a density of 0.703 g/ml. Calculate the mass of CO2(g) produced by burning one
gallon of octane. There are 3.79 liters to one gallon.
The mass of CO₂ gas produced during the combustion of one gallon of octane is 8.21 kg.
The given parameters:
Density of the octane, ρ = 0.703 g/mlVolume of octane, v = 3.79 litersThe mass of the octane burnt is calculated as follows;
[tex]m = \rho V\\\\m = 0.703 \ \frac{g}{ml} \times 3.79 \ L \ \frac{1000 \ ml}{L} \\\\m = 2,664.37 \ g[/tex]
The combustion reaction of octane is given as;
[tex]2C_8H_{18} + \ 25O_2 \ --> \ 16CO_2 \ + \ 18H_2O[/tex]
From the reaction above:
228.46 g of octane -------------------> 704 g of CO₂ gas
2,664.37 of octane --------------------> ? of CO₂ gas
[tex]= \frac{2,664.37 \times 704}{228.46} \\\\= 8,210.3 \ g\\\\= 8.21 \ kg[/tex]
Thus, the mass of CO₂ gas produced during the combustion of one gallon of octane is 8.21 kg.
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An aqueous solution was prepared by dissolving 266.07 g of AgNO3 ( 169.88 g/mol) in enough water to make a total volume of 250.0 ml. What is the molarity of the solution
Answer:
The correct answer is 6.265 M.
Explanation:
To find the molarity of the solution, we first must recall that molarity represents the number of moles of solute divided by the number of liters of solution. Thus, our first step should be to convert the solute amount in grams to moles, using the given molar mass.
266.07 g * (1 mol/169.88 g) = 1.5662 mol
Now, we can find the molarity using the following formula:
Molarity = moles solute/liters solution
M = 1.5662 mol/0.25 L
M = 6.265 M
Therefore, the molarity of the solution is 6.265 M.
Hope this helps!
i. Three different representations of glucose are
given below. Identify each type
of model.
Answer:
Ball and stick model is 3D and has the atoms depicted as different Coloured balls Conected to each other by "sticks"
fischer projection has the atoms on the side coming out of the plane, the atoms at the ends going behind (going away from you)
bond line notation Is the most common it does not show the C or H bonds but instead carbons are represented by the bends
The three structures of glucose represent three different models, they are ball and stick model, Fischer projection and bond line notation, respectively.
Glucose is a type of simple sugar (carbohydrate) that does not further hydrolyze to give monosaccharides.
Ball and stick model: The atoms are portrayed as different colored balls connected to each other by "sticks." Fischer projection: The atoms on the sides of the plane are coming out of the plane, while the atoms at the ends are moving behind.Bond line notation: It is the most frequent representation method used; it lacks C and H bonds but instead depicts carbons through bends.Therefore, the three glucose structures reflect three distinct models: the ball and stick model, the Fischer projection, and the bond line notation, respectively.
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what is the continent bellow the world?
Answer:
antarcita
Explanation:
Answer:
What is the continent bellow the world?
Antarctica is the continent below the Earth.