1. Elements of the periodic system are divided into three groups of metals, nonmetals, and metalloids. Metals in the periodic table are separated of nonmetals by metalloids. Metals are located on the left side and the nonmetals on the right side of the periodic table. On a periodic table often is showed a stair-step line from boron to polonium which represents metan-nonmetal border. The only exception is hydrogen that is nonmetal although it is situated on the left side.
2. The most numerous elements in the periodic system are metals. At the moment, there are a total of 94 metals. There are 38 transition metals, 15 lanthanides, 15 actinides, 6 alkali metals, 6 alkaline earth metals, and 14 post-transition Metals. As regarding nonmetals, their number in the periodic table is 17 and there are 7 metalloids.
3. Metal: I would choose a copper wire, made as the name suggests from a copper that has the ability to perfectly conduct electricity.
Metalloid: I would choose a smartphone that contains computer chips made from silicon that has the property of a semiconductor.
Nonmetal: I would choose a camera flash that contains xenon, a gas which produces a white flash light when it is electrically excited.
4. Boron is a metalloid with the chemical symbol B and a serial number 5. In the periodical system, it is located in the 13th group and 2nd period.
Silicon is a metalloid with the chemical symbol Si and a serial number 14. In the periodical system, it is located in the 14th group and 3rd period.
Antimony is a metalloid with the chemical symbol Sb and serial number 51. In the periodical system, it is located in the 15th group and 5th period.
When a stable diatomic molecule spontaneously forms from its atoms, what are the signs of δh°, δs°, and δg°?
The formation of a stable diatomic molecule from atoms typically results in a negative ">δH°<", a negative ">δS°<", and a negative ">δG°<". This reflects an exothermic reaction with decreased entropy, leading to spontaneity under the right temperature conditions.
When a stable diatomic molecule forms from its atoms, there are typical changes in enthalpy (">">δH°"), entropy (">">δS°"), and Gibbs free energy (">">δG°"). The formation of a stable molecule from atoms is typically exothermic, which means that energy is released, and ">">δH°" would be negative. As atoms come together to form a molecule, the system becomes more ordered, and thus, the change in entropy, ">δS°<", is negative.
According to the Gibbs free energy equation, ">δG° = δH° - TδS°<", and at a temperature (T) where this process is spontaneous, the sign of ">δG°<" would be negative because loss of heat (">">exothermic reaction") and orderliness in system (">">decreased entropy") favor the formation of the molecule.
A 15.0 kg chunk of ice falls off the top of an iceberg. If the chunk of ice falls 8.00m to to the surface of the water, what is the kinetic energy of the chunk of ice when it hits the water, and what is its velocity
What is a base used in toothpaste?
sorbitol
carrageenan
magnesium hydroxide
sodium lauryl sulfate
Answer:
The Answer is C. magnesium hydroxide
Explanation:
What process forms high non-volcanic mountain ranges?
A. One tectonic plate is splitting apart into two plates.
B. Two tectonic plates are colliding and pushing together.
C.One tectonic plate is sliding past another tectonic plate.
D. Two tectonic plates are colliding and one is sliding under the other.
The answer is D. Two tectonic plates are colliding and one is sliding under the other
2C6H5COOH + 15O2 → 14CO2 + 6H2O which of the following options gives the correct product:product ratio?
The product: product ratio in the provided chemical equation, which represents the combustion of benzene-acetic acid, is 14CO₂:6H₂O. So, for every two molecules of benzene-acetic acid reacted, 14 molecules of carbon dioxide and 6 molecules of water are produced.
Explanation:The equation provided is a chemical reaction representing the combustion of benzene-acetic acid (C₆H₅COOH). The correct product: product ratio is determined by the stoichiometric coefficients in front of each product. In this selected reaction, for every two molecules of benzene-acetic acid that react with 15 molecules of oxygen, 14 molecules of carbon dioxide (CO₂) and 6 molecules of water (H₂O) are produced.
Therefore, the product: product ratio is 14CO₂:6H₂O. This means for each reaction, you will get more than twice as much carbon dioxide as water. This ratio helps us to understand how much of each product we can expect when the reaction takes place, assuming there are sufficient reactants to complete the reaction.
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One of the compounds used to increase the octane rating of gasoline is toluene (pictured). suppose 8.30 ml of toluene (d = 0.867 g/ml) is consumed when a sample of gasoline burns in air.
The question is about the octane rating of gasoline and compound toluene that's used as an octane enhancer. An octane rating characterizes fuel's resistance to knock, originally based on a scale with n-heptane at 0 and isooctane at 100. Replacements for toxic enhancers like tetraethyl lead now include options such as toluene and ethanol.
The question involves the concept of octane rating, which is a measure of a fuel's ability to resist knocking or pinging during combustion, used in scoring gasoline. The octane scale was established using n-heptane, with an octane rating of 0, and isooctane (2,2,4-trimethylpentane), with an octane rating of 100. Fuel blends are scored against these standards to determine their octane rating. For example, a mixture of 89% isooctane and 11% n-heptane would have an octane rating of 89, representing an intermediate grade of gasoline.
Enhancers, such as toluene or ethanol, are used to increase the octane rating of gasoline. Toluene, which has a higher octane rating than 100, provides better fuel performance than pure isooctane. Historically, tetraethyl lead was used as an anti-knock agent, but due to its toxicity, it has been phased out and replaced with other substances like MTBE and ethanol.
If the empirical formula for a compound is ch2o, and the molar mass is 120.1 g/mol, the molecular formula for the compound is
Answer: Ik this is super late but for anyone looking for the real answer its this
Answer is C4H8O4
Explanation:
CH2O 12.0g+2(1.0g)+16.0g=30.0g
120.1/30.0=4
CH2O x 4 = C4H8O4
How many p electrons are in the thiazoline ring of thiamine hydrochloride? of thiamine?
Final answer:
The thiazoline ring in thiamine hydrochloride and thiamine contains two p electrons, one from each of the two carbon atoms in the ring.
Explanation:
The student has asked about the number of p electrons in the thiazoline ring of thiamine hydrochloride and thiamine. Thiazoline is a heterocyclic compound made up of a five-membered ring containing both sulfur and nitrogen atoms. In thiamine, the thiazoline ring contributes to the structure of thiamine pyrophosphate (TPP), which is the active co-enzyme form of thiamine.
In the thiazoline ring, there are two carbon atoms that can have p electrons in their p orbitals. Each carbon atom has one p electron that is not involved in sigma bonding (single covalent bonds). Therefore, the thiazoline ring contains a total of two p electrons from the carbon atoms. The nitrogen and sulfur atoms do not contribute p electrons that are relevant to the aromaticity or reactive properties of the thiazoline ring in thiamine. The thiazoline ring does not have a completely conjugated pi system like the thiazole ring, which is a closely related structure.
Classify methanol (ch3oh) as a strong electrolyte, a weak electrolyte, or a nonelectrolyte.
Explanation:
A strong electrolyte is defined as the one which contains solute that completely dissociates into ions. Strong acids will lead to the formation of strong electrolytes.
For example, HCl will make a strong electrolyte.
Whereas a weak electrolyte is defined as the one which contains solute that slightly dissociates into ions.
For example, [tex]CH_{3}OH[/tex] is a weak electrolyte.
This is because methanol when dissolved in water does not completely dissociates into ions. Therefore, very less number of ions are present into the solution and as a result, the solution will not be able to conduct electricity.
Also, oxygen atom being more electronegative in nature will hold the hydrogen atom of O-H more tightly, Hence, very less or no hydrogen ions will not present into the solution.
Therefore, we can conclude that methanol is a weak electrolyte.
Methanol, or CH3OH, is classified as a nonelectrolyte because it does not ionize or produce ions when dissolved in water, and can't therefore conduct electricity. In contrast, substances that do dissolve in water to produce ions, and can conduct electricity are electrolytes, either strong or weak.
Explanation:The student question classifies methanol (CH3OH) as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. Methanol would be classified as a nonelectrolyte.
Electrolytes are substances that when dissolved in water, they produce ions. If the process is almost 100% efficient, the substance can be considered a strong electrolyte. If only a small percentage of the substance produces ions, it is a weak electrolyte. However, substances that do not produce ions when dissolved in water are called nonelectrolytes.
Methanol, in this case, does not ionize when dissolved in water, therefore, doesn't produce ions. This classifies it as a nonelectrolyte. This can be further confirmed through a conductance test. Electrolytes can conduct electricity when dissolved in water due to the presence of ions. Since methanol doesn't produce ions when dissolved, it won't conduct electricity, substantiating its classification as a nonelectrolyte.
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What would happen if you placed your product in a drying oven set near 138 synt745?
Use the chart to determine which pair of atoms has the greatest difference in electronegativity
A. Ca-CI
B. H-CI
C. Fe-CI
D. P-CI
Consider melting ice cream. When it melts, it takes heat away from the environment and so the reaction is endothermic. When you freeze ice cream, the heat is being removed from what?
Aluminum sulfate is formed when an aluminum cation that has a 3+ charge combines with a sulfate ion that has a 2- charge. Write the formula for the compound aluminum sulfate. Font Sizes
Answer : The formula for the compound aluminum sulfate is [tex]Al_2(SO_4)_3[/tex]
Explanation :
For formation of a neutral ionic compound, the charges on cation and anion must be balanced.
The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non-metals.
In the given question, the aluminum metal forms an ionic compound with polyatomic anion (sulfate) [tex]SO_4^{2-}[/tex].
Here, aluminum is having an oxidation state of +3 called as [tex]Al^{3+}[/tex] cation and sulfate [tex]SO_4^{2-}[/tex] is an anion with oxidation state of -2. The charges are not balanced. So, the charges are balanced by the cris-cross method. Thus, the compound formed will be, [tex]Al_2(SO_4)_3[/tex]
Hence, the formula for the compound aluminum sulfate is [tex]Al_2(SO_4)_3[/tex]
The formula for aluminum sulfate is Al₂(SO₄)₃. This is because two Al³+ ions balance three SO₄²⁻ ions to achieve electrical neutrality.
Explanation:The compound aluminum sulfate is formed when an aluminum cation (Al³+) combines with a sulfate ion (SO₄²⁻). Given that atoms strive to reach electrical neutrality, the formula for this ionic compound reflects the simplest ratio that can balance the positive and negative charges. In this case, two aluminum ions (2 x +3 for a total charge of +6) are needed to balance three sulfate ions (3 x -2 for a total charge of -6), resulting in the chemical formula Al₂(SO₄)₃.
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The rate constant for a second-order reaction is 0.54 m-1s-1. what is the half-life of this reaction if the initial concentration is 0.30 m?
The correct answer is: 6.173 seconds.
Explanation:
The formula for half life (of reaction) is:
Half-life = [tex]\frac{1}{K*I}[/tex] --- (A)
Where,
K = Rate constant = 0.54 [tex]\frac{1}{ms}[/tex]
I = Initial concentration = 0.30 m
Plug in the values in equation (A):
Half-life = [tex]\frac{1}{0.54*0.30} = 6.173[/tex]
Hence, the half life is 6.173 seconds.
The half-life of a second-order reaction is [tex]\boxed{{\text{6}}{\text{.173 seconds}}}[/tex]
Further explanation:
Second-order reaction:
A reaction is said to be of second-order if its rate is proportional to the square of the concentration of one reactant. The general example of second-order reaction is,
[tex]2{\text{A}}\to{\text{P}}[/tex]
Here,
A is the reactant.
P is the product.
The rate is calculated by using the following equation:
[tex]{\text{Rate}}={\text{k}}{\left[{\text{A}}\right]^2}[/tex]
Another form of second-order reaction is as follows:
[tex]{\text{A}}+{\text{B}}\to{\text{P}}[/tex]
Here,
A and B are the two different reactants.
P is the product.
The rate is calculated by using the following equation:
[tex]{\text{Rate}}={\text{k}}\left[{\text{A}}\right]\left[{\text{B}}\right][/tex]
Half-life:
Half-life is defined as the time required to reduce the concentration of reactant to half of its initial value. It is denoted by [tex]{{\text{t}}_{1/2}}[/tex] . The general expression to calculate [tex]{{\text{t}}_{1/2}}[/tex] of second-order reaction is,
[tex]{{\text{t}}_{1/2}}=\frac{1}{{{\text{k}}{{\left[{\text{A}}\right]}_{\text{0}}}}}[/tex] …… (1)
Here,
[tex]{{\text{t}}_{1/2}}[/tex] is the half-life of the reaction.
k is the rate constant for the reaction.
[tex]{\left[ {\text{A}}\right]_{\text{0}}}[/tex] is the initial concentration of the reactant.
The rate constant for the given reaction is [tex]0.54\;{{\text{M}}^{-1}}{{\text{s}}^{-1}}[/tex] .
The initial concentration of the given reaction is 0.30 M.
Substitute these values in equation (1).
[tex]\begin{aligned}{{\text{t}}_{1/2}}&=\frac{1}{{\left({0.54\;{{\text{M}}^{ - 1}}{{\text{s}}^{ - 1}}}\right)\left( {{\text{0}}{\text{.30 M}}}\right)}}\\&=\frac{1}{{0.162\;{{\text{s}}^{ - 1}}}}\\&=6.1728\;{\text{s}}\\&\approx 6.173\;{\text{s}}\\\end{aligned}[/tex]
So, the half-life of a second-order reaction is 6.173 seconds.
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1. Calculate the moles of chlorine in 8 moles of carbon tetrachloride: https://brainly.com/question/3064603
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Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Chemical Kinetics
Keywords: second-order reaction, half-life, initial, half, 6.173 seconds, 0.30 m, k, A0, A, B, P, 2A, reactant, product, t1/2.
Match the formula for the following compound: iron (III) sulfate
FeSO4
Fe3SO4
Fe(SO4)3
Fe2(SO4)3
Answer:
D. Fe2(SO4)3
is the answer
Explanation:
Describe how you would make 1.0 l of a supersaturated solution of cdi2
Final answer:
Creating a supersaturated solution of cadmium iodide involves dissolving as much solute as possible in water at an elevated temperature and then slowly cooling the solution to room temperature without disturbance.
Explanation:
To make 1.0 L of a supersaturated solution of cadmium iodide (CdI2), first a saturated solution must be prepared at a temperature higher than room temperature by dissolving as much CdI2 as possible. This can be done by gradually adding CdI2 to a liter of water with continuous stirring while heating the solution to increase the solubility. Once no more salt can dissolve, the solution is allowed to slowly cool to room temperature, making sure to avoid any disturbance that could cause premature crystallization. As the solution cools, it becomes supersaturated because the solubility of CdI2 decreases with temperature, allowing more solute to be contained in solution than is stable at the lower temperature.
If the solution remains undisturbed, the excess solute will stay dissolved, resulting in a supersaturated solution. However, any disturbance or addition of a seed crystal will cause the excess solute to precipitate out rapidly. Therefore, care must be taken to keep the solution free from dust and vibrations that can induce crystallization.
Which of the following molecules is polar? CH4, Ch3OH, CO2
Draw the two chair conformations of cis 1 chloro 2 methylcyclohexane
The two chair conformations of cis 1 chloro 2 methylcyclohexane are shown in the image attached.
Due to the cyclohexane ring's capacity for ring flipping, isopropyl chloro-2-methylcyclohexane displays two chair conformations. The methyl group is positioned equatorially in the first conformation, while the chlorine atom is located in the axial position.
The chlorine atom is in the equatorial position and the methyl group is in the axial position in the second conformation, which has the substituents arranged in reverse order. These conformations show the dynamic character of cyclohexane rings, where substituents can be positioned in either an axial or an equatorial orientation to minimize steric hindrance between them by ring flipping.
Identify the spectator ions in the following complete ionic equation.
2
K
+
(aq)+
S
2−
(aq)+
Pb
2+
(aq)+2
NO
−
3
(aq)→PbS(s)+2
K
+
(aq)+2
NO
−
3
(aq)
Express your answers as ions separated by a comma.
A sample of gas has a volume of 5.58 l at a pressure of 715 mm hg. what is the volume of the gas when the pressure of the gas is increased to 755 mm hg?
A fatty acid with 10 carbons will be absorbed via the
The atomic mass of gold is 197 g/mole, and the density of gold is 19.3 g/cm3. using this information along with the measured value of young's modulus, calculate the speed of sound in gold.
What was the resulting molarity of your primary standard solution of potassium iodate kio3?
Determine the osmotic pressure of a solution that contains 0.048 g of a hydrocarbon solute (molar mass = 340 g/mol0
Final answer:
The osmotic pressure of a solution containing 0.048 g of a hydrocarbon with a molar mass of 340 g/mol is calculated by first finding the molarity and then using the osmotic pressure formula, resulting in approximately 0.00345 atm.
Explanation:
To determine the osmotic pressure of a solution containing a hydrocarbon solute, first, calculate the molarity of the solution. The molarity (M) is the number of moles of solute per liter of solution. Since the molar mass of the hydrocarbon is given as 340 g/mol, you can find the number of moles of solute by dividing the mass of the solute by its molar mass.
Number of moles = Mass (g) / Molar Mass (g/mol) = 0.048 g / 340 g/mol = 0.000141 mol
The volume of the solution is not given, but assuming it's 1 liter for the sake of calculation. Divide the number of moles by the volume to get molarity:
Molarity (M) = Number of moles / Volume (L) = 0.000141 mol / 1 L = 0.000141 M
To find the osmotic pressure, use the formula:
Osmotic Pressure (II) = MRT
Where M is the molarity, R is the gas constant (0.0821 L·atm/(K·mol)), and T is the absolute temperature in Kelvin. Assuming room temperature (25°C or 298 K) for the calculation:
II = (0.000141 M) x (0.0821 L·atm/K·mol) x (298 K)
Therefore, the osmotic pressure is:
II = (0.000141) x (0.0821) x (298) ≈ 0.00345 atm
Assuming equal concentrations, rank these solutions by pH.
A population in an ecosystem cannot grow indefinitely. There are limiting factors in each ecosystem that keep a population within a certain size range. Which of the following is most likely NOT a limiting factor for a population of deer in a forest ecosystem?
A. the number of perching birds present B. the amount of edible plants available C. the number of mountain lions present D. the amount of space in the forest
THE ANSWER IS
the number of perching birds present
How do chemical weathering and physical weathering affect each other?
a solution is another name for
Answer:
A solution is another name for homogeneous mixture.
Explanation
Solution or homogeneous mixture are names for the classification of matter.
Matter is classified in 2 big groups: pure substances and mixtures.
Pure substances: are those that cannot be separated into more simple ones by physics methods, and are classified in compounds and elements.
Elements: these cannot be separated into more simple substances by chemical methods, e.g.: Au, Cu, Na, Cl, etc.Compounds: these are formed by two or more elements and can be separated into more simple substances by chemical methods, e.g: H₂O, CO₂, NaCl, etc.Mixtures: are those that can be separated into more simple ones by physics methods, and are classified in homogeneous and heterogeneous.
Homogeneous mixture (solution): has the same composition in the whole mixture and its components cannot be detected easily e.g: sugar dissolved in water.Heterogeneous mixture: has different compositions in the whole mixture and its components can be detected easily in different phases, e.g.: water and cooking oil.Name the complex mncl2(en)2. the oxidation number of manganese is +2.
a mixture of iodine and sulphur crystal can be separated by treating with what ??
A mixture of iodine and sulphur can be separated by various ways:
1. Add Carbon disulphide that is (CS₂) then stir the solution and filter it . As sulphur dissolved in CS₂, so it come into filter and got separated from the mixture.
2. Take the mixture in a china dish and cover it with a inverted funnel and heat it, on heating iodine will get sublime and produces vapors . These vapors condenses at funnel and produce iodine solid.