Answer:
The answer is in the problem
Explanation:
As general rule of number of oxygen is -2:
O → -2
Alkali metals (Li, Na, K) are always +1
Na → +1
Alkali earth methals (Be, Mg, Ca...) are always +2
Ca → +2
The halogen group (F, Cl, Br...) is always -1
F → -1
The oxidation number of Si (+/- 4)
Aluminium is, usually +3
And to complete the octet rule in nitrogen, 3 electrons are required. That means:
N → -3
My swimming pool is rectangular (16 feet by 34 feet) and has a depth of 6 feet. Lets imagine that my pool water is full to the top and is heated by a laser that emits photons with a wavelength of 520 nm. The starting temperature of my pool is a chilly 52 degrees Celsius. How many moles of photons would be required to heat the pool to a balmy 80 degrees Celsius
Answer:
Number of moles of photons required = 5.04 × 10⁴ moles
Explanation:
The energy of a photon can be calculated from Planck's equation E = hc/λ
Where h = 6.63 × 10-³⁴ Js and c, the velocity of light = 3.0 × 10⁸ m/s
Energy of one mole of photons = N₀ × hc/λ
wavelength of photon, λ = 520 nm = 5.20 × 10-⁷ m
Energy of one mole of photons = 6.02 × 10²³ × 6.63 × 10−³⁴ × 3 × 10⁸/5.20 × 10-⁷
Energy of one mole of photons = 2.30 × 10⁵ J/mol
Energy required to raise the temperature of a given mass of a substance, E = mcΔT
Where m is mass of substance, c is specific heat capacity, ΔT is temperature difference
Mass ofnwternin the pool = volume × density
Volume of water = Volume of swimming pool
Volume of water = 16 × 34 × 6 ft³ = 3264 ft³
1 ft³ = 28316.8 cm³; 3264 ft³ = 28316.8 × 3264 = 92426035.2 cm³
Density of water = 1 g/cm³
Mass of water = 92426035.2 cm³ × 1 g/cm³ = 92426035.2g
ΔT = 80°C - 50°C = 30°C, c = 4.18 J/g/K
Energy required to raise 92426035.2 g water by 30° C = 92426035.2 × 4.18 × 30
Energy required = 1.16 × 10¹⁰ J
Hence, number of moles of photons required = 1.16 × 10¹⁰ J/2.30 × 10⁵ J/mol
Number of moles of photons required = 5.04 × 10⁴ moles
100.0 g of water was placed in a simple, constant-pressure calorimeter. The temperature of the water was recorded as 295.0 K. A 20.0 g copper block was heated to 353.0 K and then dropped into the water in the calorimeter. What was the final temperature of the water if the specific heat capacities of copper is 0.385 J/g K
Answer:
[tex]296.05\ \text{K}[/tex]
Explanation:
[tex]m_w[/tex] = Mass of water = 100 g
[tex]c_w[/tex] = Specific heat of water = [tex]4.184\ \text{J/g K}[/tex]
[tex]m_c[/tex] = Mass of copper = 20 g
[tex]c_c[/tex] = Specific heat of copper = [tex]0.385\ \text{J/g K}[/tex]
[tex]\Delta T_w[/tex] = Temperature change in water = [tex](T-295)[/tex]
[tex]\Delta T_c[/tex] = Temperature change in cooper = [tex](353-T)[/tex]
T = Final temperature of the system
The heat balance of the system is given by
[tex]m_wc_w\Delta T_w=m_cc_c\Delta T_c\\\Rightarrow 100\times 4.184\times (T-295)=20\times 0.385\times (353-T)\\\Rightarrow 418400\left(T-295\right)=7700\left(353-T\right)\\\Rightarrow 418400T-123428000=2718100-7700T\\\Rightarrow T=\frac{1261461}{4261}\\\Rightarrow T=296.05\ \text{K}[/tex]
The final temperature of the water is [tex]296.05\ \text{K}[/tex].
The final temperature of the water when placed in a calorimeter is 296.05K
HOW TO CALCULATE FINAL TEMPERATURE:
The final temperature of water placed in a calorimeter can be calculated using the following expression:Q(water) = - Q(copper)(m × c × ∆T) water = - {m × c × ∆T} copperWhere;
Mass of water = 100 gSpecific heat of water = 4.184 J/g KMass of copper = 20 gSpecific heat of copper = 0.385 J/g KTemperature change in water = T - 295KTemperature change in copper = T - 353K100 × 4.184 × (T - 295) = - {20 × 0.385 × (T - 353)}418.4T - 123428 = - (7.7T - 2718.1)418.4T - 123428 = -7.7T + 2718.1418.4T + 7.7T = 123428 + 2718.1426.1T = 126146.1T = 126146.1 ÷ 426.1T = 296.05KTherefore, the final temperature of the water when placed in a calorimeter is 296.05K.Learn more at: https://brainly.com/question/10987564?referrer=searchResults
You have a cold gas of atoms, and you observe that if you shine light consisting of photons with energy 10 eV through the gas, some free electrons are observed, implying that a photon of this energy is able to ionize an atom in the gas. (a) If you find that the emitted electrons from the gas have a kinetic energy of 1 eV, what is the ionization energy of the cold atom
Answer:
Ionization Energy = 9 eV
Explanation:
If we apply the law of conservation of energy to the given situation, we will get the following equation:
[tex]Energy\ of\ Photon = Ionization\ Energy + Kinetic\ Energy\ of\ Electron\\[/tex]
where,
Energy of Photon = 10 eV
Ionization Energy = ?
Kinetic Energy of Electrons = 1 eV
Therefore,
[tex]10\ eV = Ionization\ Energy + 1\ eV\\Ionization\ Energy = 10\ eV - 1\ eV[/tex]
Ionization Energy = 9 eV
How does publishing in scientific journals help ensure that science leads to
reliable results?
A. It allows results to be reviewed and reproduced by other
scientists.
B. It allows the public to decide if science is worthwhile.
C. It shows which experiments are the most popular with scientists.
D. It gives scientists a reason to do more experiments.
Answer:
A. it allows results to be reviewed and reproduced by other scientists.
a. Explain why the pie pans flew off the van de Graaf generator
b. Give a detailed explanation of why the rabbit fur and the plastic rod were attracted to each other after we rubbed them together but not before
c. Describe two things you could change to increase the force of electrical attraction between two objects (this is about Coluomb's Law).
Answer:
Static energy is an energy between two charges.
Explanation:
a). A van de Graff generator builds up a positive electric charge on the dome by separating the negative static electric charges from the positive static charge using a quickly moving belt. The positive charge collects on the large metal dome of the generator. When the charge builds up is large enough, a lighting like spark can shoot from the dome to a grounded discharge rod.
Like electric charges always repel each other, and oppositely electric charges will attract each other. When the aluminum pans are being charged by the van de Graff generator, then each of them attain the same positive polarity similar with the dome. Thus, positive charge starts to accumulate over the surface of each of the pie pan. Each aluminum pan repels the others. These repulsive forces between the pans are so strong that they succeed in overcoming the gravity force and thus the top of the pan is pushed away from the generator's dome.
b). Static electricity is produced by a concentration of negative and positive electric charges. Like charges pushes away each other while unlike charges pulls each other.
Objects generally have same numbers of positive charges as well as negative charges. And if there is any small imbalance in numbers of the charges on the object, it is charged.
Negative charges easily torn away from the materials like the fur or hair. Also, the negative charges are held on other materials like the plastics. If we rub a plastic rod with fur, the negative charges will get transferred from fur to rod. The rod gets negatively charged and the fur is positively charged. As a result, the rabbit fur and the plastic rod were attracted to each other.
c). Coulomb's law stated that :
[tex]$F=\frac{KQ_1Q_2}{d^2}$[/tex] .............(i)
where, [tex]$Q_1$[/tex] and [tex]$Q_2$[/tex] are the charges of two objects d is the distance between two objects.
As from the above equation, we can say that force of electrical attraction between two objects depends on the charges and the distance between objects.
1. The electrical force between two charged object is inversely proportional to the distance of separation between two objects.
Decreasing separation distance (d) between the objects will increase its attraction force.
2. And, increasing the charges of two objects(+ve and -ve) increases the force of attraction between two objects.
20 grams of hydrogen fluoride gas, HF, is dissolved in 0.5 liters of solution. Determine the molarity (M).
Answer:
40
Explanation:
M = n/v hope this helps :b
Terry, a student, performs a titration. He completes these steps as part of his titration procedure: 1. He cleans and rinses a burette with standardized base. 2. He fills the burette with standardized base solution. 3. He reads and records the initial burette volume. 4. He adds a base from the burette to an acid. 5. He observes a color change in the Erlenmeyer flask. 6. He stops the addition of base from the burette. 7. He reads and records the final burette volume. Which steps will provide information needed to calculate the volume of base needed to reach the equivalence point? A. 1 and 6 B. 3 and 7 C. 3, 4, and 6 D. 1, 2, and 7
Answer:
D
Explanation:
D is the answer because 2 is needed to know
Answer:
B) 3 and 7
Explanation:
i just took the test
How many moles are in 9.83 x 1021 atoms of Na
Answer:
0.016 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
We have
[tex]n = \frac{9.83 \times {10}^{21} }{6.02 \times {10}^{23} } \\ = 0.01632...[/tex]
We have the final answer as
0.016 molesHope this helps you
Consider the following data on some weak acids and weak bases:
acid base
name formula Ka name formula Kb
hydrocyanic acid HCN 4.9 x 10^-10 hydroxylamine HONH2 1.1 x 10^-1
hypochlorous acid HCIA 3.0 x 10^-18 ethylamine C2H5NH2 6.4 x 10^-4
Use this data to rank the following solutions in order of increasing pH. In other words, select a '' next to the solution that will have the lowest pH, a '' next to the solution that will have the next lowest pH, and so on.
a. 0.1 M HONH3Br
b. 0.1 M NaNO3
c. 0.1 M C2H5NH3Cl
d. 0.1 M NaF
Answer:
a < c < b < d
Explanation:
The weak acid with the lowest pKa will be the most acidic. In the other way, the conjugate base which the acid is weakest will be strongest.
The weak base with the lowest pKb will be the most basic. And the conjugate base of the weakest base will be a strongest acid.
Using the values:
Ka HCN = 4.9x10⁻¹⁰
Kb HONH2 = 1.1x10⁻⁸
Ka HClA 3.0x10⁻⁸
Kb C2H5NH2 = 6.4x10⁻⁴
The NaNO3 is the conjugate base of a strong acid as HNO3. That means its solutions are almost neutral
The HONH3Br is the conjugate acid of a weak base. Its solutions will be acidics
C2H5NH3Cl is the conjugate acid of a weak base as ethylamine, its solutions will be acidic.
As ethylamine has a lower pkb than hydroxylamine, the conjugate acid of hydroxylamine will be more acidic.
NaF is the conjugate base of a weak acid as HF. Its solutions will be basics
The order in increasing pH is:
HONH3Br < C2H5NH3Cl < NaNO3 < NaF
a < c < b < dकरताह!
गर्मियों में घड़े का जल ठंडा क्यों होता है?
Answer:
I don't understand the question
Explanation:
what is your name
How many liters would you need to make a 0.8 M solution with 20 grams of lithium chloride?
Answer:
0.5875L
Explanation:
concentration = mole/ volume
n(LiCl) = 20 / (7 + 35.5) = 0.47 mol
volume = mole / conc.
volume = 0.47 /0.8
= 0.5875 dm³ = 0.5875L
what is the definition for domain bacteria?
Answer:
Domain is the............. highest taxonomic rank in the hierarchical biological classification system, ........above the kingdom level. There are three domains of life, the Archaea, the Bacteria,,,,,,,,, and the Eucarya.
Reword, taken off the internet.
Explanation:
How many Liters are in 98.2 moles of neon?
Answer:
2200 L
Explanation:
There are 22.4 L in 1 mole of neon so if you have 98.2 L, then you have 98.2 mole x (22.4 L/mole) = 2200 L of neon.
ii) Sodium thiosulphate dissolves in dilute nitric acid at a steady rate. Copy out which
of the following changes would quicken up the reaction- 3
a. Cooling the reacting vessel to drop the temperature.
b. Breaking the reactants into smaller pieces.
c. Adding more concentrated acid.
d. Using more sodium thiosulphate.
Answer:
d
Explanation:
g A student determines the number of moles of water in a hydrated metal oxide by weighing a clean, dry crucible and lid while the crucible is empty, then reweighing the crucible and lid with a sample of the hydrate, heating the crucible and lid with a Bunsen burner and then reweighing the crucible and lid with the sample after cooling to room temperature. Which error will result in too high a value for the amount of water of hydration
The question is incomplete, the complete question is;
A student determines the number of moles of water in a
hydrated metal oxide by weighing a clean, dry crucible
and lid while the crucible is empty, then reweighing the
crucible and lid with a sample of the hydrate, heating the
crucible and lid with a Bunsen burner and then
reweighing the crucible and lid with the sample after
cooling to room temperature. Which error will result in
too high a value for the amount of water of hydration?
(A) The heating is conducted only once instead of the
three times recommended by the procedure.
(B) The lid is left off the crucible when it is weighed
with the hydrated oxide.
(C) The metal oxide reacts partially with oxygen in the
air, forming a compound in a higher oxidation state.
(D) Some of the heated oxide is spilled from the crucible
before it can be weighed.
Answer:
(D) Some of the heated oxide is spilled from the crucible
before it can be weighed.
Explanation:
It is possible to determine the number of moles of water in a hydrated metal oxide by weighing a clean, dry crucible and lid while the crucible is empty, then reweighing the crucible and lid with a sample of the hydrate. The crucible and lid with the sample are heated, cooled and reweighed.
As this process is going on, suppose some of the heated oxide is spilled from the crucible, then the mass of heated or anhydrous oxide decreases leading to a consequent increase in the number of moles of water in the hydrated metal oxide, hence the answer above.
The too high a value for the amount of water of hydration error is occur due to heating of given hydrated sample.
What is hydrated compounds?
Hydrated compounds are those compounds in which water molecule is present with the normal compound.
To get the correct value of weight of hydrated compound, first we have to weigh the empty crucible and lid and then with sample of compound in the crucible and lid. After this substract empty weigh of crucible & lid from the sample-crucible-lid weigh. If we substract the weigh from heated sample crucible and lid, then we get the error because the hydrated water molecule may decompose due to heating and moles of water increases.
Hence, error will occur if we heat the sample.
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If there are 1.55 x 1024 molecules of hydrogen peroxide (H2O2), what is the mass of the
sample?
Answer:
87.54 g of H₂O₂
Explanation:
From the question given above, the following data were obtained:
Number of molecules = 1.55×10²⁴ molecules
Mass of H₂O₂ =.?
From Avogadro's hypothesis,
6.02×10²³ molecules = 1 mole of H₂O₂
Next, we shall determine the mass of 1 mole of H₂O₂. This can be obtained as follow:
1 mole of H₂O₂ = (2×1) + (2×16)
= 2 + 32
= 34 g
Thus,
6.02×10²³ molecules = 34 g of H₂O₂
Finally, we shall determine mass of H₂O₂ that contains 1.55×10²⁴ molecules. This can be obtained as follow:
6.02×10²³ molecules = 34 g of H₂O₂
Therefore,
1.55×10²⁴ molecules
= (1.55×10²⁴ × 34)/6.02×10²³
1.55×10²⁴ molecules = 87.54 g of H₂O₂
Thus, 87.54 g of H₂O₂ contains 1.55×10²⁴ molecules.
What is the energy of a photon?
A. A photon has no energy.
B. The energy of a photon is hxc.
c. The energy of a photon is hx 2.
D. The energy of a photon is h* f.
Which statement about nuclear fission and nuclear fusion is not correct?
A. Both processes change atoms of one element to another element.
B. Both processes can release huge amounts of energy.
C. Both processes conserve mass.
D. Both processes produce dangerous radiation.
The statement, that describes about nuclear fission and nuclear fusion is "both processes can release huge amounts of energy."
What is nuclear fission and fusion?Nuclear fission is the process by which an atom's nucleus breaks into two or more smaller nuclei. Nuclear fusion is the process by which two light atomic nuclei merge to produce a single heavier one, releasing huge quantities of energy in the process.
Fusion and fission are both nuclear reactions that yield significant amounts of energy that can be used to generate power. However, fission is the splitting of atoms, whereas fusion is the joining of them.
To put in another way, while both nuclear reactions that generate energy, the methods are vastly different. They both produce a lot of energy.
Hence the correct answer is B.
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Answer:it’s not B
Explanation:
Which type of metal ions tends to absorb light in the visible range?
Transition metal ions tends to absorb light in the visible range.
What are Transition Metals?Transition metal is defined as an element having a d subshell that is partially filled with electrons, or an element that has the ability to form stable cations with an incompletely filled d orbital.
The transition metals are located towards the middle of the periodic table between the highly reactive metals and the noble gases.
They are the only elements that may use electrons in the next to highest—as well as the highest—energy level as valence electrons.
Transition metals are unusual in having very similar properties even with different numbers of valence electrons.
Therefore, Transition metal ions tends to absorb light in the visible range.
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Which of the following accurately describes the function of the muscular
system?
O A. To prevent and fight disease
B. To provide support for the body
C. To get rid of wastes and excess water
D. To allow the body to move
Question 3 of 10
Which best explains why the sun maintains its size and shape?
A. Pressure caused by high temperatures are balanced by gravity.
B. The sun burns from its core to its surface.
C. Forces exerted by orbiting planets cause the sun to rotate.
SUBMIT
Answer:A
Explanation:
where do you think water vapor in air comes from?
A 3mL sample of a 200 Molar solution is left open on a lab
counter for two weeks, after which the concentration of the solution is 6 M. What is the new volume of the solution?
Answer: New volume of the solution is 100 mL.
Explanation:
Given: [tex]V_{1}[/tex] = 3 mL, [tex]M_{1}[/tex] = 200 M
[tex]M_{2}[/tex] = 6 M, [tex]V_2[/tex] = ?
Formula used to calculate the new volume of solution is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute the values into above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\200 M \times 3 mL = 6 M \times V_{2}\\V_{2} = \frac{200 M \times 3 mL}{6 M}\\= 100 mL[/tex]
Thus, we can conclude that new volume of the solution is 100 mL.
The formula for the pH of a solution of hydronium ions is given by the logarithmic equation pH= -log[h3o^+], where [H3o^+] is the hydronium ion concentration. Find the pH of a certain agricultural product with the hydronium ion concentration of 4.7x10^-4
The pH is =?
Answer:
pH = 3.3
Explanation:
Step 1: Given data
Concentration of hydronium ions in the agricultural product ([H₃O⁺]): 4.7 × 10⁻⁴ M
Step 2: Calculate the pH of the agricultural product
We will use the definition of pH.
pH = -log [H₃O⁺]
pH = -log 4.7 × 10⁻⁴
pH = 3.3
Since the pH < 7, the agricultural product is acidic.
What will change more solid NiCl2 is added
The city of Annandale has been directed to upgrade its primary wastewater treatment plant to a secondary treatment plant with sludge recycle that can meet an effluent standard of 11 mg/l BOD5. The following data are available: Flow = 0.15 m3/s, MLSS = 2,000 mg/L. Kinetic parameters: K, = 50 mg/L, Hmax = 3.0 d-, kų = 0.06 d-1, Y = 0.6 Existing plant effluent BOD5 = 84 mg/L. a. Calculate the SRT (Oc) and HRT (0) for the aeration tank. b. Calculate the required volume of the aeration tank. c. Calculate the food to microorganism ratio in the aeration tank. d. Calculate the volumetric loading rate in kg BOD3/m3-d for the aeration tank. e. Calculate the mass and volume of solids wasted each day, when the underflow solids concentration is 12,000 mg/L. 10 A
If I had 3.50 x 10 24molecules of Cl2 gas, how many grams is this?
Answer:
412 g Cl₂
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 3.50 × 10²⁴ molecules Cl₂
[Solve] grams Cl₂
Step 2: Identify Conversions
Avogadro's Number
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of Cl₂ - 2(35.45) = 70.9 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 3.50 \cdot 10^{24} \ molecules \ Cl_2(\frac{1 \ mol \ Cl_2}{6.022 \cdot 10^{23} \ molecules \ Cl_2})(\frac{70.9 \ g \ Cl_2}{1 \ mol \ Cl_2})[/tex][DA] Divide/Multiply [Cancel out units]: [tex]\displaystyle 412.072 \ g \ Cl_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
412.072 g Cl₂ ≈ 412 g Cl₂
Pls help ASAP it’s timing meeee!!!!!
How will the temperature change if you increase the mass of the gas molecules?
The temperature of a gas sample rises, the molecules quicken, and as a result, the root mean square molecular speed rises.
What is meant by temperature?Degree of warmth or coolness determined by a specific scale
The temperature of a gas sample rises, the molecules quicken, and as a result, the root mean square molecular speed rises.
In a gas, the speed of the molecules is inversely related to the molar mass of the gas and inversely proportional to temperature.
The rate of diffusion is inversely related to the square root of the gas's molar mass, according Graham's law of Diffusion.
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A group of elements with similar properties, which usually falls into columns on the periodic table. A.period b.ductile c.atomis d.family
