Answer:
N 2 H4
Explanation:
A 46.6-mgmg sample of boron reacts with oxygen to form 150 mgmg of the compound boron oxide. Part A What is the empirical formula of boron oxide
Answer:
B₂O₃
Explanation:
Step 1: Calculate the mass of oxygen in 150 mg of boron oxide
Of 150 mg of boron oxide, 46.6 mg belong to boron. The mass of oxygen is:
150 mg - 46.6 mg = 103.4 mg
Step 2: Calculate the percent by mass of each element
We will use the following expression.
%Element = mElement/mCompound × 100%
%B = 46.6 mg/150 mg × 100% = 31.1%
%O = 103.4 mg/150 mg × 100% = 68.9%
Step 3: Divide each percentage by the atomic mass of the element
B: 31.1/10.81 = 2.88
O: 68.9/16.00 = 4.31
Step 4: Divide both numbers by the smallest one (2.88)
B: 2.88/2.88 = 1
O: 4.31/2.88 ≈ 1.5
Step 5: Multiply both numbers by 2 so that they are integers
B: 1 × 2 = 2
O: 1.5 × 2 = 3
The empirical formula is B₂O₃.
(URGENT!) Which of these graphs best models the waves in the four locations?
(100 points)
i can not understand the question. There seems to be missing info
Write the number of sig. fig. in four numbers given in the sentence below. An (one) octopus has 8 legs. 13 octopi have 104 legs.
Give four answers.
A. Infinity, Infinity, Infinity, Infinity
B. 1, 1, 2, 3
C. Infinity, Infinity, 2, 3
D. No answer text provided.
Answer:
1, 1, 2, 3
Explanation:
The numbers 1 and 8 both have 1 sig. fig.
The number 13 has 2 sig. figs.
The number 104 has 3 sig. figs.
The following physical constants are for water, H2O.
The specific heat capacity of the solid = 2.09 J/g oC
The specific heat capacity of the liquid = 4.18 J/g oC
The specific heat capacity of the vapor = 2.09 J/g oC
∆Hfus = 6.02 kJ/mol; ∆Hvap = 40.7 kJ/mol Freezing point = 0.0oC; Boiling point = 100.0oC
How much heat(in kJ) is required to warm 10.0 grams of ice at -5.0oC to a temperature of 70.0oC?
Answer:
[tex]Q\approx6.4~kJ[/tex]
Explanation:
Quantity of heat required by 10 gram of ice initially warm it from -5°C to 0°C:
[tex]Q_1=m.C_s.\Delta T[/tex]
here;
mass, m = 10 g
specific heat capacity of ice, [tex]C_s=2.09~J.g^{-1}.^{\circ}C^{-1}[/tex]
change in temperature, [tex]\Delta T=(5-0)=5^{o}C[/tex]
[tex]Q_1=10\times2.09\times 5[/tex]
[tex]Q_1=104.5~J[/tex]
Amount of heat required to melt the ice at 0°C:
[tex]Q_2=m.\Delta H_{fus}[/tex]
where, [tex]\Delta H_{fus}=6020~J/mol[/tex]
we know that no. of moles is = (wt. in gram) [tex]\div[/tex] (molecular mass)
[tex]Q_2=\frac{10}{18} \times 6020[/tex]
[tex]Q_2=3344.44~J[/tex]
Now, the heat required to bring the water to 70°C from 0°C:
[tex]Q_3=m.C_L.\Delta T[/tex]
specific heat of water, [tex]C_L=4.18~J/g/^oC[/tex]
change in temperature, [tex]\Delta T=(70-0)=70^oC[/tex]
[tex]Q_3=10\times 4.18\times 70[/tex]
[tex]Q_3=2926~J[/tex]
Therefore the total heat required to warm 10.0 grams of ice at -5.0°C to a temperature of 70.0°C:
[tex]Q=Q_1+Q_2+Q_3[/tex]
[tex]Q=104.5+3344.44+2926[/tex]
[tex]Q=6374.94~J[/tex]
[tex]Q\approx6.4~kJ[/tex]
c) Solar energy is the source of all forms of energy.give reasons
Answer:
All energy is made by the sun because without the sun there would be no humans to produce other energy
Explanation:
We use many different forms of energy here on earth, but here’s the thing: almost all of them originate with the sun, not just light and heat (thermal) energy! The law of conservation of energy says that energy can’t be created or destroyed, but can change its form. And that’s what happens with energy from the sun—it changes into lots of different forms:
Plants convert light energy from the sun into chemical energy (food) by the process of photosynthesis. Animals eat plants and use that same chemical energy for all their activities.
Heat energy from the sun causes changing weather patterns that produce wind. Wind turbines then convert wind power into electrical energy.
Hydroelectricity is electrical energy produced from moving water, and water flows because heat energy from the sun causes evaporation that keeps water moving through the water cycle.
Right now, much human activity uses energy from fossil fuels such as coal, oil, and natural gas. These energy sources are created over very long periods of time from decayed and fossilized living matter (animals and plants), and the energy in that living matter originally came from the sun through photosynthesis.
solar panel shows what is the ultimate source of energy
What mass of steam initially at 120oC is needed to warm 200g of water in a glass container from 20.0 oC to 50.0 oC
Complete question:
What mass of steam initially at 120 ⁰C is needed to warm 200g of water in a 100 g glass container from 20.0 oC to 50.0 ⁰C
Answer:
the initial mass of the steam is 10.82 g
Explanation:
Given;
mass of water, m₁ = 200 g
mass of the glass, m₂ = 100 g
temperature of the steam = 120 ⁰C
initial temperature of the water, 20⁰ C
final temperature of the water, = 50⁰ C
let the mass of the steam = m
specific heat capacity of water c = 1 cal/g ⁰ C
specific heat capacity of glass c₂ = 0.2 cal/g ⁰ C
laten heat of vaporization of steam L = 540 cal/g
Apply principle of conservation energy;
Heat given off by the steam = Heat absorbed by water + heat absorbed by glass
[tex]mc\Delta T_1 + mL + mc\Delta T_2 = m_1c\Delta T_3 + m_2c_2\Delta T_3\\\\mc\Delta T_1 + mL + mc\Delta T_2 = [m_1c + m_2c_2]\Delta T_3[/tex]
m(1) (120 - 100) + m(540) + m(1) (100 - 50) = [200(1) + 100(0.2)] (50 - 20)
20m + 540m + 50m = 6600
610 m = 6600
m = 6600 / 610
m = 10.82 g
Therefore, the initial mass of the steam is 10.82 g
Calculate the mass of butane needed to produce 80.0g of carbon dioxide
Answer:
Multiply the number of moles of butane by its molar mass, 58.12g/mol, to produce the mass of butane. Mass of butane = 18.8g.
14 protons,14 electrons and 14 neutrons
the answer is silicon!!
I have an unknown volume of gas held at a temperature of 115 K in a container with a pressure of 60atm. If by increasing the temperature to 225 K and decreasing the pressure to 30. atm causes the volume of the gas to be 29 liters, how many liters of gas did I start with?
SHOW YOUR WORK
Explanation:
here is the answer to your question.
Many chemistry problems result in equations of the form
1.77 X100.298-z)
When this equation is solved, the two values of the unknown are ________ and ________
Answer:
When this equation is solved, the two values of the unknown are 0.0643 and -0.082
Explanation:
Given
[tex]1.77 * 10^{-2} = \frac{x^2}{0.298 - x}[/tex] --- the actual equation
Required
The values of x
We have:
[tex]1.77 * 10^{-2} = \frac{x^2}{0.298 - x}[/tex]
Cross Multiply
[tex]1.77 * 10^{-2} * (0.298 - x)= x^2[/tex]
Multiply both sides by 100
[tex]1.77 * (0.298 - x)= 100x^2[/tex]
Open bracket
[tex]0.52746 - 1.77x= 100x^2[/tex]
Rewrite as:
[tex]100x^2 + 1.77x - 0.52746 =0[/tex]
Using quadratic formula:
[tex]x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}[/tex]
Where:
[tex]a = 100; b = 1.77; c = -0.52746[/tex]
So, we have:
[tex]x = \frac{-1.77 \± \sqrt{1.77^2 - 4*100*- 0.52746 }}{2*100}[/tex]
[tex]x = \frac{-1.77 \± \sqrt{214.1169}}{2*100}[/tex]
[tex]x = \frac{-1.77 \± 14.63}{200}[/tex]
Split
[tex]x = \frac{-1.77 + 14.63}{200}\ or\ x = \frac{-1.77 - 14.63}{200}[/tex]
[tex]x = \frac{12.86}{200}\ or\ x = \frac{-16.40}{200}[/tex]
[tex]x = 0.0643\ or\ x = -0.082[/tex]
g n the following three compounds(1,2,3) arrange their relative reactivity towards the reagent CH3Cl / AlCl3. Justify your order
Answer:
3 > 2> 1
Explanation:
Aromatic compounds undergo electrophilic substitution reaction which passes through a positively charged intermediate to yield the product.
Substituted benzenes may be more or less reactive towards electrophilic aromatic substitution than benzene molecule depending on the nature of the substituent.
Certain substituents increase the ease of reaction of benzene towards aromatic substitution.
If we look at the compounds closely, we will notice that toluene reacts readily with CH3Cl / AlCl3. This is because, the methyl group is electron donating hence it stabilizes the positively charged intermediate produced in the reaction.
Carbonyl compounds are electron withdrawing substituents hence they decrease the magnitude of the positive charge and hence decrease the rate of electrophilic aromatic substitution.
. Gastric juice, the digestive fluid produced in the stomach, contains hydrochloric acid, HCl. Milk of Magnesia, a suspension of solid Mg(OH)2 in an aqueous medium, is sometimes used to neutralize excess stomach acid. Write a complete balanced equation for the neutralization reaction, and identify the conjugate acid-base pairs.
Answer:
Mg(OH)2 + 2HCI = MgCI2 + 2H2O
Explanation:
Please correct me if I am wrong
Write the complete electron configuration for the common monatomic ion formed by the element bromine, Br.
Answer:
iron
Explanation:
Calculate the vapor pressure (in torr) at 298 K in a solution prepared by dissolving 46.8 g of the non-volatile non-electrolye glucose in 117 g of methanol. The vapor pressure of methanol at 298 K is 122.7 torr. Enter your answer to 2 decimal places.
Answer: The total partial pressure of the solution is 131.37 torr.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
For glucose:Given mass of glucose = 46.8 g
Molar mass of glucose = 180 g/mol
Plugging values in equation 1:
[tex]\text{Moles of glucose}=\frac{46.8g}{180g/mol}=0.26 mol[/tex]
For methanol:Given mass of methanol = 117 g
Molar mass of methanol = 32 g/mol
Plugging values in equation 1:
[tex]\text{Moles of methanol}=\frac{117g}{32g/mol}=3.66 mol[/tex]
Mole fraction is defined as the moles of a component present in the total moles of a solution. It is given by the equation:
[tex]\chi_A=\frac{n_A}{n_A+n_B}[/tex] .....(2)
where n is the number of moles
Putting values in equation 2:
[tex]\chi_{methanol}=\frac{3.66}{0.26+3.66}=0.934[/tex]
Raoult's law is the law used to calculate the partial pressure of the individual gases present in the mixture. The equation for Raoult's law follows:
[tex]p_A=\chi_A\times p_T[/tex] .....(3)
where [tex]p_A[/tex] is the partial pressure of component A in the mixture and [tex]p_T[/tex] is the total partial pressure of the mixture
We are given:
[tex]p_{methanol}=122.7torr\\\chi_{methanol}=0.934[/tex]
Putting values in equation 3, we get:
[tex]122.7torr=0.066\times p_T\\\\p_T=\frac{122.7torr}{0.934}=131.37torr[/tex]
Hence, the total partial pressure of the solution is 131.37 torr.
which of the following is the unit of surface tension?
Answer:
it should be N/m or newton per meter.
The first law of thermodynamics defines chemical energy. defines entropy. is a statement of conservation of energy. provides a criterion for the spontaneity of a reaction.
Answer: The first law of thermodynamics is a statement of conservation of energy.
Explanation:
According to the first law of thermodynamics, heat provided to a system is actually the sum of internal energy and work done by the system or on the system.
Mathematically, [tex]\Delta Q = \Delta U + \Delta W[/tex]
The first law of thermodynamics also means that energy can neither be created nor it can be destroyed. Hence, energy is conserved.
Thus, we can conclude that the first law of thermodynamics is a statement of conservation of energy.
State two conditions necessary for an esterification reaction to take place
Explanation:
Esterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.
Answer:
The Esterification ProcessThe Esterification ProcessEsterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.
The Esterification ProcessEsterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.Once the -OH has been removed, the hydrogen on the alcohol can be removed and that oxygen can be connected to the carbon. Because the oxygen was already connected to a carbon, it is now connected to a carbon on both sides, and an ester is formed.
The Esterification ProcessEsterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.Once the -OH has been removed, the hydrogen on the alcohol can be removed and that oxygen can be connected to the carbon. Because the oxygen was already connected to a carbon, it is now connected to a carbon on both sides, and an ester is formed.The methyl acetate that was formed is an ester. In this image, the green circle represents what was the carboxylic acid (in this case acetic acid), and the red circle represents what was the alcohol (in this case methanol):
This reaction lost an -OH from the carboxylic acid and a hydrogen from the alcohol. These two also combine to form water. So any esterification reaction will also form water as a side product.
How much would the freezing point of water decrease if 4 mol of sugar were added to 1kg of water?
Answer:
7.44 C is the answer of the question.
Explanation:
Draw a sketch showing what osmotic pressure is. Label on the sketch solute, solvent, hypertonic, hypotonic and semi permeable membrane.
Self-esteem and loss of control are key
factors of our mental well being.
A-True
B-False
You have been sent a sample of aspirin to analyse for impurities. Describe how you could
determine if the sample is pure aspirin or not using your knowledge of chemistry.
Answer:
The aspirin could be determined if pure or not by testing it with FeCI3 (aq)
The sample of aspirin can be tested for it's purity by treating it with compound of ferric chloride.
What is a compound?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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the Wavelength of a microwave is______than the wavelength of visible light
(Please help)
Answer:
The wavelength of a microwave is LONGER than the wavelength if visible light.
Part A: Calculate the mass of butane needed to produce 75.6g of carbon dioxide.
Part B: Calculate the mass of water produced when 5.48g of butane reacts with excess oxygen.
Answer:
Multiply the number of moles of butane by its molar mass, 58.12g/mol, to produce the mass of butane. Mass of butane = 18.8g.
Explanation:
Part B:
The mass of water produced when 4.86 g of butane(C4H10) react with excess oxygen is calculated as below
calculate the moles of C4H10 used = mass/molar mass
moles = 4.86g/58 g/mol =0.0838 moles
write a balanced equation for reaction
2 C4H10 + 13 O2 = 8 CO2 + 10 H2O
by use of mole ratio between C4H10 to H2O which is 2:10 the moles of
H20= 0.0838 x10/2 = 0.419 moles of H2O
mass = moles x molar mass
=0.419 molx 18 g/mol = 7.542 grams of water is formed
Combustion of 29.26 gg of a compound containing only carbon, hydrogen, and oxygen produces 33.86 gCO2gCO2 and 13.86 gH2OgH2O. Part A What is the empirical formula of the compound
Answer:
C2H4O3
Explanation:
Empirical formula is defined as the simplest whole number ratio of atoms present in a molecule.
To solve this question we need to find the moles of carbon = Moles of CO2, the moles of hydrogen (Using moles of H2O) and the moles of oxygen (Finding the mass of the mass of each atom) as follows:
Moles Carbon -Molar mass CO2: 44.01g/mol-:
33.86g CO2 * (1mol/44.01g) = 0.769 moles CO2 = Moles C * (12g/mol) =
9.23g C
Moles Hydrogen -Molar mass H2O: 18.01g/mol-
13.86g H2O * (1mol/18.01g) = 0.770 moles H2O * (2mol H / 1mol H2O) = 1.54 moles H * (1g/mol) = 1.54g H
Moles Oxygen:
Mass: 29.26g - 9.23g C - 1.54g H = 18.49g O * (1mol/16g) = 1.156 moles O
Dividing each number of moles in the moles of C (Lowe number of moles):
C = 0.769 moles C / 0.769 moles C = 1
H = 1.54 moles H / 0.769 moles C = 2
O = 1.156 moles O / 0.769 moles C = 1.5
As the number must be a whole number each ratio twice:
C = 2
H = 4
O = 3
Empirical formula is:
C2H4O3In a classroom, students who are biochemistry majors are learning about the overall organization of biological membranes. However, one of the students finds a WRONG explanation about the fluid mosaic model from a website and bring it up in a discussion. Which of the following is a WRONG explanation?
a. An explanation of the two-dimensional solutions of oriented lipids and globular proteins.
b. The lipid bilayer is a solvent for integral membrane proteins.
c. All membrane proteins diffuse laterally and freely in the lipid matrix.
d. None of the answers is correct.
e. The lipid bilayer is a permeability barrier for integral membrane proteins.
Answer:
e. The lipid bilayer is a permeability barrier for integral membrane proteins.
Explanation:
Integral membrane proteins enter the lipid bilayer by translocon channel which gives nascent polypeptide segment a chance to partition itself into lipid bilayer hydrophobic core.
If 6.50 L of water vapor at 50.2 °C and 0.121 atm reacts with excess iron, how many grams of iron(III) oxide will be produced?
2Fe(s)+3H2O(g)⟶Fe2O3(s)+3H2(g)
Answer:
1.60 g of Fe₂O₃
Explanation:
We'll begin by calculating the number of mole water that reacted. This can be obtained as follow:
Volume (V) = 6.50 L
Temperature (T) = 50.2 °C = 50.2 + 273 = 323.2 K
Pressure (P) = 0.121 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Number of mole (n) =?
PV = nRT
0.121 × 6.5 = n × 0.0821 × 323.2
0.7865 = n × 26.53472
Divide both side by 26.53472
n = 0.7865 / 26.53472
n = 0.03 mole
Thus, 0.03 mole of water reacted.
Next, we shall determine the number of mole of Fe₂O₃ produced from the reaction. This can be obtained as follow:
2Fe + 3H₂O —> Fe₂O₃ + 3H₂
From the balanced equation above,
3 moles of H₂O reacted to produce 1 mole Fe₂O₃.
Therefore, 0.03 mole of H₂O will react to produce = (0.03 × 1)/3 = 0.01 mole of Fe₂O₃.
Thus, 0.01 mole of Fe₂O₃ was produced from the reaction.
Finally, we shall determine the mass of 0.01 mole of Fe₂O₃. This can be obtained as follow:
Mole of Fe₂O₃ = 0.01 mole
Molar mass of Fe₂O₃ = (56×2) + (16×3)
= 112 + 48
= 160 g/mol
Mass of Fe₂O₃ =?
Mass = mole × molar mass
Mass of Fe₂O₃ = 0.01 × 160
Mass of Fe₂O₃ = 1.60 g
Therefore, 1.60 g of Fe₂O₃ were produced.
The speed of light_____ meters per second
☛ 299,792,458 meters per second.
mass of exactly 1 mole of arsenic
Answer:
The average mass of one atom of arsenic is 74.92 amu, and the mass of one mole of arsenic atoms is 74.92 grams.
The mass of one mole of arsenic atoms is 74.92 grams.
Calculation,
Mass of one mole of arsenic = Mass of 1 arsenic atom × [tex]N_{A}[/tex]
Where, [tex]N_{A}[/tex] = Avogadro's number = 6.022 × [tex]10^{23}[/tex]
Mass of one arsenic atom = 74.921 u
One u = 1.66 × [tex]10^{-27}[/tex] kg
And,
Mass of one mole of arsenic atom = 6.022 ×[tex]10^{23}[/tex] × 74.921 × 1.66 × [tex]10^{-27}[/tex]×[tex]10^{3}[/tex] kg
Mass of one mole of arsenic atom = 74.92 [tex]gmol^{-1}[/tex]
What is molar mass?The mass of one mole of a substance in grams is called molar mass.The unit is [tex]gmol^{-1}[/tex].To learn more about molar mass,
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3. The electrolyais of water produces oxygen gas at the rate of 32.5 mL/min in a certain experiment.
What volume of oxygen gas can be produced in 7.50 min?
Answer:
243.75 mL
Explanation:
In 1min 32.5 mL of oxygen
In 7.5 min electrolysis of water produces
(32.5mL × 7.5 min)/ 1min
= 243.75mL
A major component of gasoline is octane when octane is burned in air it chemically reacts with oxygen to produce carbon dioxide and water what mass of carbon dioxide is produced by the reaction of oxygen
gasoline is the chemical that is coming out of the air