Answer:
verdadero
Explanation:
porque esoo [tex]\lim_{n \to \infty} a_n x_{123} \frac{x}{y} \sqrt[n]{x} x^{2} \sqrt{x} \pi \neq \lim_{n \to \infty} a_n \left[\begin{array}{ccc}1&2&3\\4&5&6\\7&8&9\end{array}\right] \int\limits^a_b {x} \, dx \left \{ {{y=2} \atop {x=2}} \right.[/tex]
why it is wrong to use the term 'Pure Air' in Science?
Explanation:
Air is a combination of other gases, dust particles, pollens, spores etc. This means that air is a heterogeneous mixture where particles are unevenly distributed.
Air is not considered as a pure substance because there is not one element present in air. A substance which contains only one type of element is called a pure substance.
Therefore, it is wrong to use the term 'Pure Air' in Science.
Which of the following substances did Robert Brown observed upon forming the concept of Brownian motion?
A. Talc powder suspended in water
B. Talc powder suspended in air
C. Pollen grains suspended in water
D. Pollen grains suspended in air
Answer:
Talc powder suspended in air
Waves are generated when energy passes through causing them to move matter through ____ ?
Answer:
sending heat waves and vibrations
What is a chemical reaction that absorbs heat called?
A. A thermal energy reaction
B. A thermodynamic reaction
C. An endothermic reaction
D. An exothermic reaction
Answer:
maybe it's c. An endothermic reaction
An endothermic reaction is a chemical reaction that absorbs heat. Therefore, the correct option is option C.
An endothermic reaction in thermochemistry would be any thermodynamic process that results in a rise in the system's enthalpy H (or heat capacity U). A closed system typically helps to absorb thermal energy from the surroundings during such a process, which causes heat transfer through into system.
It could be a physical process, like the melting of ice cubes, or a chemical process, like the dissolution of ammonium nitrate (NH[tex]_4[/tex]NO[tex]_3[/tex]) throughout water (H[tex]_2[/tex]O). An endothermic reaction is a chemical reaction that absorbs heat.
Therefore, the correct option is option C.
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Ammonia fumes is found to permanently fog soft contact lenses. Students wearing soft contact lenses should be particularly careful when doing this experiment. Will wearing goggles or other eye protection remove the risk or danger for these students?
Answer:
Wearing goggles or other eye protection will remove the risk or danger for these students
Explanation:
Soft contact lenses are usually worn in the eyes and Ammonia compound may fog the lens thereby retaining the particles of ammonia which could spread to the eye and cause a lot of damage to it.
Using a goggle is usually more effective in dealing with the risks involved as they prevent the Ammonia from having any contact at all with the eyes due to the far proximity to the eyes when compared to contact lenses.
(iii) Give areason why the nitrogen gas obtained is not pure
Answer:
jhhhhhhhhh
Explanation:
dffffffffffffg
What is the pOH of 0.5 M KOH?
Answer:
pOH = 0.3
Explanation:
As KOH is a strong base, the molar concentration of OH⁻ is equal to the molar concentration of the solution. That means that in this case:
[OH⁻] = 0.5 MWith that information in mind we can calculate the pOH by using the following formula:
pOH = -log[OH⁻]pOH = -log(0.5)pOH = 0.3Sound travels through the air in
Answer:
Sound travels through the air in approximately 332 metres per second?
Explanation:
is this what you are looking for>
What happens to milk when it is poured from a rectangular container into a round glass? (2 points)
Group of answer choices
The milk changes state from a liquid to a solid in the round glass.
The volume of the milk increases when it is poured into a round glass.
The volume of the milk decreases when it is poured into a round glass.
The milk takes the shape of the round glass.
Answer:
The milk takes shape of the round glass.
What is the molarity of a solution containing 0.32 moles of NaCI in 3.4 liters
Answer:
.094 M
Explanation: 0.32molNaCl/ 3.4L = .094M
QUESTION 3 (a) Ammonium sulphate, (NH),50, is a soluble salt and it is used in agriculture as fertiliser. 5 g of ammonium sulphate is dissolved in 1 litre of water to produce ammonium sulphate solution. (Relative atomie mass: H = 1, N = 14,0 = 16, )
Calculate
(1) the number of inoles of dissolved ammonium sulphate
(ii) the number of molecules present in the ammonium sulphate solution.
(iii) the number of positive ions present in the ammonium sulphate solution
(iv) the number of negative ions present in the ammonium sulphate solution
(v) the total number of ions present in the ammonium sulphate solution
Answer:
The equation: (NH₄)₂SO₄ = 2NH4(+) + SO4(-2)
The number of moles = 5 g / 132.14 g/mol = 0.038 mol
The number of molecules = 0.038 X 6.022x10^23 = 2.29x10^23
the number of positive ions present in the ammonium sulphate solution:
2 positive ions for every 1 molecule of (NH₄)₂SO₄
so 2 x 2.29x10^23 = 4.58x10^23
the number of negative ions present in the ammonium sulphate solution
1 negative ion for every 1 molecule of (NH₄)₂SO₄
so 1 x 2.29x10^23 = 2.29x10^23
the total number of ions present in the ammonium sulphate solution
4.58x10^23 + 2.29x10^23 = 6.87x10^23
What will be the mass of 2 moles of propane gas?
a 20 grams
b 44 grams
c88 grams
d 30 grams
Answer: 88 grams
Explanation:
g 1. Write a mechanism for the Grignard reaction of benzophenone with phenylmagnesium bromide. Be as complete as possible and show electron flow for all steps.
Answer:
See explanation and image attached
Explanation:
The reaction between benzophenone and phenylmagnesium bromide is a Grignard reaction.
A Grignard reagent is any alkyl magnesium halide compound. In this case, the Grignard reagent is phenylmagnesium bromide.
Reaction of Grignard reagent with a ketone yields all alcohol. Thus, the reaction of benzophenone with phenylmagnesium bromide yields triphenyl methanol.
The mechanism of the reaction and all electron movements are shown in the image attached to this answer.
Calculate the amount of heat needed to melt 160. g of solid octane (C8H18 ) and bring it to a temperature of 99.2 degrees c. Round your answer to 3 significant digits. Also, be sure your answer contains a unit symbol.
Answer: The amount of heat needed to melt the given amount of octane is 84.6 kJ
Explanation:
We know:
Boiling point of Octane = [tex]125.6^oC[/tex]
Few processes involved are:
(1): [tex]C_8H_{18} (s) (-57^oC, 219K) \rightleftharpoons C_8H_{18}(s) (-57^oC, 219K[/tex]
(2): [tex]C_8H_{18}(l) (-57^oC, 219K) \rightleftharpoons C_8H_{18}(l) (99.2^oC,372.2K)[/tex]
Calculating the heat absorbed for the process having same temperature:
[tex]q=n\times \Delta H_{(f)}[/tex] ......(i)
where,
q is the amount of heat absorbed, n is the moles of sample and [tex]\Delta H_{(f)}[/tex] is the enthalpy of fusion
Calculating the heat released for the process having different temperature:
[tex]q=n\times C_{l}\times (T_2-T_1)[/tex] ......(ii)
where,
n = moles of sample
[tex]C_{l}[/tex] = specific heat of liquid
[tex]T_2\text{ and }T_1[/tex] are final and initial temperatures respectively
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] ......(3)
Given mass of octane = 160. g
Molar mass of octane = 114.23 g/mol
Plugging values in equation 3:
[tex]\text{Moles of octane }=\frac{160.g}{114.23g/mol}=1.40 mol[/tex]
For process 1:We are given:
[tex]n=1.40mol\\\Delta H_{fusion}=20.740 kJ/mol[/tex]
Putting values in equation (i), we get:
[tex]q_1=1.40mol\times 20.470kJ/mol\\\\q_1=28.658kJ[/tex]
For process 2:We are given:
[tex]n=1.40mol\\C=255.68J/mol^oC\\T_2=99.2^oC\\T_1=-57^oC[/tex]
Putting values in equation (ii), we get:
[tex]q_2=1.40mol\times 255.68J/mol^oC\times (99.2-(-57))\\\\q_2=55912.10J=55.912kJ[/tex]
Calculating the total amount of heat released:
[tex]Q=q_1+q_2[/tex]
[tex]Q=[(28.658)+(55.912)]kJ=84.6kJ[/tex]
Hence, the amount of heat needed to melt the given amount of octane is 84.6 kJ
Which equation represents an addition reaction?
Answer:
Reactions in which a multiple bond between two atoms becomes partly or fully saturated by covalent attachments... A typical addition reaction may be illustrated by the hydrochlorination of propene (an alkene), for which the equation is CH3CH = CH2 + HCl → CH3C+HCH3 + Cl− → CH3CHClCH3.
Explanation:
thank me later
CH3CH = CH2 + HCl → CH3C+HCH3 + Cl− → CH3CHClCH3.
This reaction is the example of addition reaction.
What is an addition reaction?An addition reaction is defined as a chemical reaction in which two or more molecules combine to produce a bigger molecule. This type of reaction is called addition reaction.
So we can conclude that the formation of bigger molecule is the example of addition reaction.
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A hot air balloon has an air vent that keeps the air pressure inside and outside the same. Allen observes that a hot air balloon rises up when the gas molecules inside it are heated. Which
of the following laws is used to understand the behavior of the gas and why?
a) The high temperature brings the gas molecules closer together according to Charles's law because this law describes how a gas will behave at constant pressure
b) The high temperature makes the gas molecules spread apart according to Charles's law because this law describes how a gas will behave at constant pressure.
c) The high temperature lowers volume according to Boyle's law because this law describes how a gas will behave when the number of moles remains constant.
d) The high temperature ralses volume according to Boyle's law because this law describes how a gas will behave when the number of moles remains constant.
Answer:
B - The high temperature makes the gas molecules spread apart according to Charles's law because this law describes how a gas will behave at constant pressure.
Explanation:
Charle's Law describes the relationship between temperature and volume, where increased temperature leads to increased volume. When volume is increased, that means the gas molecules are more spread apart and have more random motion. Therefore, the answer is B.
The high temperature causes the gas molecules to spread apart according to Charles's law because explain how a gas, behave at constant pressure.
What does Charles law state?The physical principle called Charles' law which states that the volume of a gas equals a constant value many by its temperature as measured on the Kelvin scale.
Volume regaled by a clinched amount of gas is directly proportional to its temperature and pressure if remains steady.
Thus, option "B" is correct, the volume of a gas equals a constant value.
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Why would iron filings rust faster than an iron nail?
Answer:
Rust forms on iron filings faster than on a large iron block
Explanation:
Because the surface area exposed to air in the refrigerator is greater than its area by mass, the rust-forming reaction occurs faster.
Hypochlorous acid decays in the presence of ultraviolet radiation. Assume that degradation occurs accord- ing to first-order kinetics and the rate of degradation was measured to be 0.12 day−1 (at a particular sun- light intensity and temperature). Given this, how long does it take for the concentration of hypochlorous acid to reach nondetectable levels (0.05 mg · L−1) if the initial concentration were 3.65 mg · L−1?
Answer:
35.75 days
Explanation:
From the given information:
For first-order kinetics, the rate law can be expressed as:
[tex]\mathsf{In \dfrac{C}{C_o} = -kt}[/tex]
Given that:
the rate degradation constant = 0.12 / day
current concentration C = 0.05 mg/L
initial concentration C₀ = 3.65 mg/L
[tex]\mathsf{In( \dfrac{0.05}{3.65})= -(0.12) t}[/tex]
㏑(0.01369863014) = -(0.12) t
-4.29 = -(0.12)
t = -4.29/-0.12
t = 35.75 days
(answer is a period table element!) When apprehending a suspect, try not to put your ____ on him.
Answer:
H
Explanation:
try not to put your hands on him
HELP!!! i will give brainliest!!
Different chemical elements have different chemical symbols, and this is determined by their atomic structure. Look at the two chemical symbols in the image. Compare and contrast the atomic symbols and the atomic structure of fluorine and oxygen.
Answer:
Explanation:
fluorine have gained one electron that is why the sign is -1. they both have different number of protons. They have different neutron numbers. F have 10 and O have 8.
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You have 100 mL of a solution of benzoic acid in water; the amount of benzoic acid in the solution is estimated to be about 0.30 g. The distribution coefficient of benzoic acid in diethyl ether and water is approximately 10. Calculate the amount of acid that would be left in the water solution after four 20-mL extractions with ether.
Answer:
0.00370 g
Explanation:
From the given information:
To determine the amount of acid remaining using the formula:[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{(initial \ mass \ of \ solute )_{water}} = (\dfrac{v_2}{v_1+v_2\times k_d})^n[/tex]
where;
v_1 = volume of organic solvent = 20-mL
n = numbers of extractions = 4
v_2 = actual volume of water = 100-mL
k_d = distribution coefficient = 10
∴
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = (\dfrac{100 \ ml}{100 \ ml +20 \ ml \times 10})^4[/tex]
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = (\dfrac{100 \ ml}{100 \ ml +200 \ ml})^4[/tex]
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = (\dfrac{1}{3})^4[/tex]
[tex]\dfrac{(final \ mass \ of \ solute)_{water}}{0.30 \ g} = 0.012345[/tex]
Thus, the final amount of acid left in the water = 0.012345 * 0.30
= 0.00370 g
You have reacted 100.00mL of 1.353M aqueous sulfuric acid with 12.618g of sodium hydroxide solid. If all of the heat generated by this reaction is transferred to a 1.317kg block of copper metal initially at 16.82°C, what is the final temperature of the block of copper metal? (Specific heat of copper = 0.375J/g*°C)
Answer:
70.137 °C
Explanation:
The reaction generated from the question can be expressed as:
[tex]2NaOH_{(s)} + H_2SO_{4(aq)} \to Na_2SO_{4(aq)} +2H_2O_{(l)}[/tex]
The enthalpy reaction:
[tex]\Delta H^0 _{rxn} = \sum \Delta H^0 _{f (products)} - \sum \Delta H^0 _{f (reactants)}[/tex]
[tex]\Delta H^0 _{rxn} =[2 \times \Delta H^0 _f (H_2O) + \Delta H^0 _f (Na_2SO_4) ] -[2 \Delta \times H^0 _f (NaOH) + \Delta H^0 _f (H_2SO_4) ][/tex]
Repacing the values of each compound at standard enthalpy conditions;
[tex]\Delta H^0 _{rxn} =[2 \times -279.4 + (-1384.49)]-[(2\times -418) -913]\ kJ[/tex]
[tex]\Delta H^0 _{rxn} =-194.29 \ kJ[/tex]
no of moles of NaOH = 12.618g/39.99 g/mol
= 0.3155 mol
no of moles of H₂SO₄ = molarity of H₂SO₄ × Volume
= 1.3553 mol/L × 100 × 10⁻³ L
= 0.13553 mol
From the reaction,
1 mol of NaOH = 2 × mol of H₂SO₄
Since mol of NaOH is greater than that of H₂SO₄, then NaOH is the excess reagent and H₂SO₄ is the limiting reactant
∴
1 mol of H₂SO₄ yields = - 194.29 kJ
0.13553 mol of H₂SO₄ will yield;
[tex]= \dfrac{-194.29 \ kJ}{1 \ mol} \times 0.13553 \ mol[/tex]
= -26.332124 kJ
= -26332.12 J
Finally,
Heat(q) = [tex]m_{(copper)} \times C_{(copper)}\times \Delta T[/tex]
26332.12 J = 1.317 × 10³ g × 0.375 J/g°C ×ΔT
26332.12 J = 493.875 J/° C × ΔT
26332.12 / 493.875 = ΔT
ΔT = 53.317 °C
[tex]T_f - T_i = 53.317 ^0 C[/tex]
[tex]T_f[/tex]- 16.82 °C = 53.317 °C
[tex]T_f[/tex] = (53.317 + 16.82) °C
[tex]T_f[/tex] = 70.137 °C
Which of the following is a nonpolar molecule?
O A. A nitrogen molecule (N2)
B. A nitrogen monoxide molecule (NO)
C. A linear nitrogen oxide molecule (N20) with nitrogen in the center
D. A bent nitrogen dioxide molecule (NO) with nitrogen in the center
Answer: The correct option is A) a nitrogen molecule.
Explanation:
Polar covalent molecules are defined as chemical compounds in which the difference in electronegativity between the atoms is not equal to 0. These molecules are formed by heteronuclear molecules.
Heteronuclear molecules are defined as the molecules which are formed by the combination of more than one type of atom having a different nucleus.
Non-polar covalent molecules are defined as chemical compounds in which the difference in electronegativity between the atoms is equal to 0. These molecules are formed by homonuclear molecules.
Homonuclear molecules are defined as the molecules which are formed by the combination of one type of atom having the same nucleus.
From the given options:
A) A nitrogen moleculeIt is a homonuclear molecule formed by the combination of 2 nitrogen atoms
B) A nitrogen monoxide moleculeIt is a heteronuclear molecule formed by the combination of 1 nitrogen and 1 oxygen atoms
C) A linear nitrogen oxide molecule [tex](N_2O)[/tex] with nitrogen in the centerIt is a heteronuclear molecule formed by the combination of 2 nitrogen and 1 oxygen atom and has some dipole moment. Thus, is considered a polar molecule
D) A bent nitrogen dioxide molecule [tex](NO_2)[/tex] with nitrogen in the centerIt is a heteronuclear molecule formed by the combination of 1 nitrogen and 2 oxygen atoms and has some dipole moment. Thus, is considered a polar molecule
Hence, the correct option is A) a nitrogen molecule.
What is used to measure P? To measure T? in Gas laws
Answer:
P = pressure T = temperature
Share the same molecular formula but have different connectivity of atoms and different physical properties.
Answer:
Constitutional Isomers
Explanation:
Constitutional isomers can be regarded as structural isomers ,these are compounds that have the same molecular formula with different structural formulas. Example is Butane and isobutane; both compound posses the same molecular formula(C4H10) with different structural formulas. compounds of Constitutional isomers are differ in term of connectivity, which
is the way the constituent atoms are been connected to another. It should be noted that Constitutional Isomers Share the same molecular formula but have different connectivity of atoms and different physical properties.
The [OH-] of a solution is 7.89 10^-12 M. What is the pH of the solution? it acidic or basic? *
Answer: pH = 2,897 , basic[tex][H+][OH-] = 10^{-14} ==> [H+] = \frac{10^{-14}}{7,89*10^{-12} } =\frac{1}{789} \\pH= -lg([H+]) = 2,897 \\pH<7 ==> basic[/tex]
Explanation:
If two gases, A and B, in separate 1 liter containers exert
pressures of 2 atm and 3 atm respectively, what will be the
pressure exerted when both gases are put together in a single
1 liter container?
Answer:
5Atm
Explanation:
I just guess and it’s right
You dissolve 14 g of Mg(NO3)2 in water and dilute to
750 mL. What is the molarity of this solution?
Answer:
0.127M
Explanation:
Molarity of a solution = number of moles (n) ÷ volume (V)
Molar mass of Mg(NO3)2 = 24 + (14 + 16(3)}2
= 24 + {14 + 48}2
= 24 + 124
= 148g/mol
Using the formula, mole = mass/molar mass, to convert mass of Mg(NO3)2 to mole
mole = 14g ÷ 148g/mol
mole = 0.095mol
Volume = 750mL = 750/1000 = 0.75L
Molarity = 0.095mol ÷ 0.75L
Molarity = 0.127M
What are fluids? Why are they so called?
Fluids are liquid and gases. They take the shape of their containers. They are called fluids because of their ability to flow.
A solution containing 1.22 g of a diprotic acid H2CH2O4 (malonic acid)
was titrated with 45.5 mL of NaOH to reach the second equivalence
point. What is the concentration of the NaOH solution? (MW_malonic
acid = 104.06 g/mol)
Answer:
0.515 M
Explanation:
The reaction that takes place is:
H₂CH₂O₄ + 2NaOH → Na₂CH₂O₄ + 2H₂OFirst we convert 1.22 g of malonic acid into moles, using its molar mass:
1.22 g ÷ 104.06 g/mol = 0.01172 molThen we convert 0.01172 malonic acid moles into NaOH moles, using the stoichiometric coefficients of the balanced reaction:
0.01172 mol H₂CH₂O₄ * [tex]\frac{2molNaOH}{1molH_2CH_2O_4}[/tex] = 0.02344 mol NaOHFinally we calculate the concentration of the NaOH solution, using the number of moles and given volume:
Converting 45.5 mL ⇒ 45.5/1000 = 0.0455 L
0.02344 mol / 0.0455 L = 0.515 M