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A sample of aluminum requires 341 J of energy to raise the temperature from 18.0ºC to 55.0ºC. Calculate the mass of the aluminum sample.
Answer:
10.22g
Explanation:
Using the formula as follows:
Q = m × c × ∆T
Where;
Q = amount of heat required (J)
m = mass of substance (g)
c = specific heat of substance (J/g°C)
∆T = change in temperature (°C)
According to the information given in this question;
Q = 341J
m = ?
∆T = 55.0ºC - 18.0ºC = 37°C
c of aluminum = 0.902J/g°C
Using Q = m × c × ∆T
341 = m × 0.902 × 37
341 = 33.374m
m = 341 ÷ 33.374
m = 10.22g
Octane (C8H18) is found in gasoline. It is burned for fuel in a combustion
reaction. The unbalanced combustion reaction for octane is shown below.
C8h18+ O2 → C02 + H2O + heat
When the reaction is balanced, how many carbon dioxide molecules are
produced for every octane molecule burned?
Answer:
Explanation:
It's 8
1. How many grams of water are in a cup containing
0.1 moles of H2O?
Answer:
Explanation:
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Food Science is the study of the physical, biological, and chemical makeup of food; the
causes of food deterioration; and the concepts ulderlying food processing.
True
False
What do greenhouse gases do on Earth?
Answer:
It holds heat from the sun close to Earth.
Explanation:
Hope this helps and have a great day. :)
Isoniazid is used in the treatment of tuberculosis and multiple sclerosis. Identify each lone pair as either localized or delocalized. Justify your answer in each case.
Answer:
Please find the complete question and its solution in the attached file:
Explanation:
How many electrons are in the highest occupied energy level of a neutral chlorine atom?
Mercury: Mineral or Not Mineral? Mineral Not Mineral
Answer:
not a mineral but is a “mineraloid
Explanation:
not mineral
Explanation: its an element but it is not a mineral
How many moles of sodium hydroxide would have to be added to 150 mL of a 0.483 M acetic acid solution, in order to prepare a buffer with a pH of 4.480
Answer:
0.068 moles of sodium hydroxide would have to be added to 150 mL of a 0.483 M acetic acid solution
Explanation:
As we know
pH = pKa + log [salt]/[acid]
4.480= 4.74 + log [salt]/[acid]
log [salt]/[]acid] = -0.06
[salt]/[acid] = 0.87
moles acid = 0.150 L x 0.483 mol/L = 0.07245 moles acid
x/0.07245-x = 0.87
X- 0.07245 X = 0.87 *0.07245
X = 0.068 moles
Magnesium hydroxide and sodium hydroxide are both strong bases. The pH of a saturated solution of sodium hydroxide is greater than 14. The pH of a saturated
solution of magnesium hydroxide is about 10.2. Why do the solutions have different pH values?
Answer: Solubility of NaOH is greater and there are more OH- ions in solution.
Explanation: Reactions : NaOH (s) ⇒ Na+ (aq) + OH- (aq)
Mg(OH)2 (s) ⇒ Mg2+ (aq) + 2 OH-(aq)
Although in same amount of moles, Mg(OH)2 produces
two (OH-)-ions in water solution, solubility of Mq(OH)2 is smaller.
Concentration [OH-]ions is smaller in saturated water solution
of Mg(OH)2
What are two main groups of forces
Answer:
There are 2 types of forces, contact forces and act at a distance force. Every day you are using forces. Force is basically push and pull. When you push and pull you are applying a force to an object.
Explanation:
What cell structure is best represented by the image?
A.
a non-permeable cell wall
B.
a selectively permeable membrane
C.
a waterproof nuclear envelope
D.
a permeable exoskeleton
Answer:where is the image
Explanation:
Answer:
B.
a selectively permeable membrane
Explanation:
Given 23 g of potassium nitrate per 25 g of water, what temperature should create a saturated solution?
Answer:
At about 51 °C
Explanation:
Hello there!
In this case, according to the attached solubility chart of potassium nitrate, our first step for this problem is to calculate the grams of this solute in 100 g given that 23 g are soluble in 25 g of water:
[tex]\frac{23g}{25g}=\frac{x}{100g}\\\\x= \frac{23g*100g}{25g}=92g[/tex]
Thus, such solubility of 92 g in 100 g of water is exhibited at about 51 °C.
Regards!
Can someone please help me out, I need to do this asap. Tired of bots responding my questions and would have to report it instantly
Answer:
Solution given:
Required reaction is:
2H2+O2➔2H2O
now
10.
oxygen have 16 amu than total mass in the left side of oxygen is:
16×2=32 amu of Oxygen
11.
total mass of Oxygen in product side is;
16×2=32 amu of Oxygen
Strontium has 3 stable isotopes with mass numbers 86, 87 and 88. Their relative abundances are 9.97%, 7.0% and 82.6% respectively. How do the number of electrons and the electron configurations compare for atoms of the three isotopes
Answer:
38 and [Kr] 5s2.
Explanation:
The number of electrons and the electronic configurations are the same for the three isotopes of Strontium because in isotopes number of neutron increases not number of proton or electron. Isotope of element having the same atomic number but with different atomic masses due to increase the number of neutrons in each isotope. So the number of electron in all isotopes are the same i.e. 38 and the electronic configuration is also the same i.e. [Kr] 5s2.
which formulas could represent the empirical formula and the molecular formula of a given compound?
A. CH2O, C4H6O4
B. CHO, C6H12O6
C. CH4, C5H12
D. CH2, C3H6
Answer:
d
Explanation:
d
The formulas which could represent the empirical formula and the molecular formula of a given compound are CH₂, C₃H₆ as the smallest possible is 2 which on multiplying the subscripts of empirical formula give molecular formula.
What is empirical formula?Empirical formula of a compound is defined as the simplest whole number ratio of atoms which are present in a compound.It does not make any mention of the arrangement of atoms or the number of atoms. The empirical formula gives information about the ratio of number of atoms which are present in a compound.
Molecular formula is determined from the empirical formula by dividing the molar mass of a compound by the empirical formula mass. The resultant which should be a whole number or very close to the whole number , then the subscripts are multiplied by the whole number to get the molecular formula.
Learn more about empirical formula,here:
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Suppose the available nutrients in the soil of an ecosystem decrease. Over time, which adaptation is MOST LIKELY to evolve among the plants that survive there?
Answer:
Root system will become larger or extend farther
Explanation:
If nutrient in soil decrease, the plant's roots system will likely become larger and extend out deeper and farther to get all the nutrients it possibly can
A student determines that the theoretical yield of CaCO3, from a precipitation reaction is 21.5 grams
However, this student only recovers 19.9 grams of precipitate through filtration of the solution.
What would be this student's percent yield?
A. 92.6%
B. 0.93%
C. 108%
D. 85.6%
Answer:
92.6
Explanation:
Which force is most responsible for binding together an atom’s protons and neutrons?
electrostatic
gravitational
nuclear
magnetic
gravitational force is most responsible for binding together an atom’s protons and neutrons.
What is gravitational force?In physics, gravity (from Latin gravitas 'weight') is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is by far the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a result, it has no significant influence at the level of subatomic particles. However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light.
On Earth, gravity gives weight to physical objects, and the Moon's gravity causes tides in the oceans. Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing the circulation of fluids in multicellular organisms. Investigation into the effects of weightlessness has shown that gravity may play a role in immune system function and cell differentiation within the human body.
The gravitational attraction between the original gaseous matter in the Universe allowed it to coalesce and form stars which eventually condensed into galaxies, so gravity is responsible for many of the large-scale structures in the Universe. Gravity has an infinite range, although its effects become weaker as objects get farther away.
Learn more about gravitational force
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A sample of sodium-24 decays to 1/16of its original size in 60 hours. What is the half-life of Na-24
Answer:
The correct answer is - 15 hours.
Explanation:
Half-life an element is the time required to decay the half amount of the initial amount of the element and is represented by t1/2.
The formula for the calculating initial amount
n(i)=n(r)⋅2^n
where
n(i) - the initial number of moles of element
n(r) - the number of moles remained amount after the given time
n - the number of periods,
= time T, where T is the half-life.
n(i)=n(r)⋅2^n
n(i)/n(r) =2^n
1/16 =2^n
n= 4
The half life = 60/n
= 60/4
= 15 hours.
How many Moles are there in 8.55 x 10^24 molecules of NaCl?
Answer:
Moles = avogadro's constant divided by the number of molecules.
1.. A saturatedsolutionA.contains more solute thansolvent.B.contains more solvent thansolute.C.contains equal moles of solute andsolvent.D.contains the maximum amount of solute that will dissolve in that solvent at that temperature.E.contains a solvent with only sigma bonds and no pi bonds (i.e. only single bonds, with no doubleor triplebonds).
Answer:
D. contains the maximum amount of solute that will dissolve in that solvent at that temperature.
Explanation:
Solubility is a term used to describe how readily a substance can be dissolved in a solvent to form a solution. Thus, a substance is said to be soluble if it dissolves completely in a solvent and insoluble if it doesn't dissolve or only dissolves partially.
For example, sodium chloride (NaCl) when mixed with water dissociates into sodium and chloride ions. Thus, salt (sodium chloride) is said to be soluble because it dissolves completely in water.
Hence, a compound that dissolves in water to produce an aqueous solution is said to be soluble in water. Also, the solute of an aqueous solution that conducts electricity is called an electrolyte.
In Chemistry, dissolution can be defined as the process of dissolving or dissociating a solute in solid, liquid or gaseous phase into fragmented particles by a solvent in order to form a solution. For dissolution to occur in solids, the crystalline structure of the substance must be broken up so as to release ions, atoms or molecules to produce a solution. For liquid and gases, the substance to be dissolved must form a non-covalent bond with the solvent to produce a solution.
Generally, a saturated solution contains the maximum amount of solute that will dissolve in that solvent at that temperature.
15. Objects can have kinetic energy, potential energy, or both. Energy can be in the form of motion. Energy can
also be stored by objects in various ways, including position, chemical bonds, or physical state.
Which statement is true? And why?
a. An object’s mass has no effect on its potential energy.
b. Potential energy is converted to kinetic energy as a stationary object begins to move.
c. Kinetic energy is converted to potential energy as a stationary object begins to move.
d. A stretched rubber band stores no energy.
Answer: b because Potential energy is converted to kinetic energy as a stationary object begins to move.
Explanation:
Help!!I’ll put brainlist!
2. What is the molarity of a 0.30 liter solution containing 0.50 moles of NaCl?
3. Calculate the molarity of 0.289 moles of FeCl, dissolved in 120 ml of solution?
4. If a 0.075 liter solution contains 0.0877 moles of Cuco, what is the molarity?
Answer:
hope this helps
Explanation:
2. Well, we take the quotient...concentration=moles of solutevolume of solution
Explanation:
And thus concentration has the units of mol⋅L−1...
And so in this given scenario, the quotient gives....
concentration=[NaCl(aq)]=0.50⋅mol0.30⋅L=1.67⋅mol⋅L−1.
What are the concentrations with respect to [Na+], and [Cl−]?
3. molarity=2.41molL
Explanation:
Molarity=Moles of soluteLiters of solution
Moles=0.289
Solution=120mL=0.12L
Therefore,
Molarity=0.289mol0.12L≈2.41molL
4. 1.169 mol/L
Explanation:
From the question given, we obtained the following information:
Volume = 0.075 L
Mole of CuCo = 0.0877 moles
Molarity =..?
Molarity is simply defined as the mole of solute per unit litre of the solution. It is represented mathematically as:
Molarity = mole /Volume
With the above formula, we can obtain the molarity of the solution as follow:
Molarity = 0.0877 mol / 0.075 L
Molarity = 1.169 mol/L
Therefore, the molarity of the solution is 1.169 mol/L
Write and balance the equation for the neutralization reaction between phosphoric acid and
sodium hydroxide.
Answer: H3PO4(aq)+3NaOH(aq)→Na3PO4(aq)+3H2O(l)
Explanation:
A 1 liter solution contains 0.383 M hydrofluoric acid and 0.510 M potassium fluoride.
Addition of 0.096 moles of calcium hydroxide will:
(Assume that the volume does not change upon the addition of calcium hydroxide.)
Raise the pH slightly
Lower the pH slightly
Raise the pH by several units
Lower the pH by several units
Not change the pH
Exceed the buffer capacity
Answer:
Lower the pH slightly
Explanation:
The mixture of HF, hydrofluoric acid and KF, potassium fluoride produce a buffer that is defined for the equilibrium:
HF(aq) → H⁺(aq) + F⁻(aq)
The buffer can maintain the pH of a solution despite the addition of strong bases or acids.
The reaction of HF with Ca(OH)2 is:
2HF + Ca(OH)2 → 2H2O + CaF2
That means the calcium hydroxide is decreasing the concentration of HF. Based on the equilibrium, the H+ and F- ions will decrease in order to produce more HF. As H+ is decreasing due the equilibrium and not for the addition of a strong base, the pH is decreasing slightly.
Why do we need cells to divide? Give two examples.
Answer:
Cells need to divide to reproduce.
Explanation:
They go through numerous stages, such as mitosis to further replicate themselves. They can't get things done alone, so they have to work in numbers.
What number should be written in front of Na to balance the equation?
Na + MgCl2 → NaCl + Mg
1
2
3
4
In order to balance the chemical equation, the coefficient of Na should be 2.
Combustion is an exothermic reaction where the reactants are combined with ____ to produce CO2 + H2O + ____
Answer:
The answer is oxygen gas.