Answer:
D
Explanation:
The correct answer would be that the thermal energy of the sun is transferred to the pavement.
Thermal energy refers to the internal energy possessed by a system by virtue of the movement of molecules within such a system. In other words, it is the heat energy possessed by a system.
When the thermal energy from the sun warms the pavement, it means that the thermal energy from the sun has been successfully transferred to the pavement. Thermal energy can be transferred by conduction, convection, or by radiation depending on whether the system is a solid, liquid, gas respectively.
The correct option is, therefore, D.
a. For a chemistry lab final exam, a high school chemistry student was given a 1-mole sample of CaCl2 and a 1-mole sample of MgCl2 but was not told which sample was which. He was to identify the powders.
He looked up the enthalpies of formation for both of the chemicals and calculated the ΔHreaction for dissolving each powder: CaCl2 (s) Ca 2+ (aq) + 2Cl – (aq), and MgCl2 (s) Mg 2 (aq) + 2Cl – (aq). He then put each powder in a coffee-cup calorimeter and added water.
When sample A dissolved, the temperature increased by 0.74°C. When sample B dissolved, the temperature increased by 0.39°C. Which chemical was A, and which was B? Use the table of enthalpies of formation to help you. Explain your reasoning.
Ca^2+ ion is smaller than Mg^2+ ion hence it has a greater heat of formation or lattice energy.
When a crystal lattice is formed, the energy that is released if the component ions of the compound are brought together from infinity is called the lattice energy. It is the energy released when a crystal lattice is formed from its component ions.
The question lets us know that the heat released by the compounds depends on the energy released upon formation of the compound. Hence, the higher the energy released upon formation, the higher the magnitude of heat released upon dissolution of the compound.
Recall that lattice energy depends on the size of the ions. Thus, the smaller the ions, the higher the lattice energy.
Ca^2+ is smaller than Mg^2+ hence more energy is given off when CaCl2 is formed than when MgCl2 is formed.
As stated above, the greater the lattice energy, the greater the heat released when the lattice dissolves and the higher the rise in temperature.
Putting all these together, Sample A must be CaCl2 while sample B must be MgCl2.
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Question 14 (Essay Worth 10 points) (03.05 MC) Use complete sentences to differentiate between acids and bases on the basis of touch. Give an example of each type.
Answer:
Acid is a molecule capable of donating hydrogen ion and they form aqueous solutions with a sour taste while base is a substance that accepts proton from proton donor and in aqueous solution, they have an astringent or bitter taste. Moreover, a good example for base is sodium hydrogen carbonate as baking soda or baking powder and for acid, the most common example is the acetic acid or vinegar.
Answer:
Well, for starters, bases mostly consist of soaps and cleaning products, acids consist of vinegar,lemon,and stuff like that. Most acids on the basis of touch can burn your skin or be very sour, unlike bases which are more soapy and have a cleaner touch.A good example of an acid is vinegar, which can be used for cleaning but can also be used for making foods, on the other hand. A good example of a base is dish soap. It is used for cleaning.
Explanation:
i just did the exam and got a 100
hii pls help me to balance the equation and state the symbols thanksss
Ca(s)+ H2O (l)----->H2 +Ca(oH)2
Ca(s)+2H2O(l)----->H2(g)+Ca(oH)2
I hope this helps
sorry if it's wrong
Cellular respiration occur within ______ of a cell.
Answer:
The mitochondria
Explanation:
Its where cellular respiration occurs
9. During an experiment the students prepared three mixtures A)Starch in water B) Sodium chloride solution C) Tincture of Iodine. i) Students observed a visible beam of light through mixture A. Why? ii) Tincture of lodTe did not show Tyndall effect. Explain reason. ill) How can you relate particle size to Tyndall effect?
Answer:
See explanation
Explanation:
Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.
In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.
Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.
A precipitation reaction 2. A Lewis acid-base reaction the produces a coordination complex: A Lewis acid-base reaction the produces a coordination complex 3. An oxidation-reduction reaction that is also a synthesis reaction: An oxidation-reduction reaction that is also a synthesis reaction Column B a. Pb2 (aq0 CrO42-(aq) --> PbCrO4(s) b. 2 Mg(s) O2(g) -> 2 MgO(s) c. Ag (aq) 2NH3(aq) --> [Ag(NH3)2] (aq)
Answer:
Pb2+ (aq) + CrO42-(aq) --> PbCrO4(s) - A precipitation reaction
2 Mg(s) + O2(g) -> 2 MgO(s) - An oxidation-reduction reaction that is also a synthesis reaction
Ag^+ (aq) + 2NH3(aq) --> [Ag(NH3)2]^+ (aq) - A Lewis acid-base reaction the produces a coordination complex
Explanation:
A precipitation reaction is one in which two aqueous reactants yields an insoluble product called a precipitate as shown in reaction 1 above.
In the second reaction Mg is oxidized from zero to + 2 while oxygen was reduced from zero to -2 as the MgO is formed hence the reaction is an oxidation-reduction reaction that is also a synthesis reaction.
In the third reaction, Ag^+ a Lewis acid reacts with NH3, a lewis base to yield the complex [Ag(NH3)2]^+.
Suppose 'A' is a liquid aromatic compound with molecular weight 78 and burns with sooty flame. a.Give the name of the compound 'A' b.write the molecular structure of 'A' C. What is the product when 'A' is treated with ? i.conc.HNO3 with conc.H2SO4 as catalyst ii.Halogen (cl2)in presence of sunlight and mention the use of the product obtained
Aromatic compounds are compounds that contain carbon-carbon multiple bonds.
The question did not mention that a heteroatom is present in the compound so we can assume that there is none of such. In that case, the compound contains only hydrogen and carbon.
So,
(CH)n = 78
where n is the number of each atom present.
(12 +1)n = 78
n = 78/13
n = 6
The molecular formula of the compound is C6H6
When C6H6 is treated with .conc.HNO3/conc.H2SO4 the compound shown in image 1 is formed. The reaction occurs at the C-C multiple bond.
When C6H6 is reacted with chlorine in the presence of sunlight, hexachlorobenzene (shown in image 2 attached) is formed.
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A 1.732 g sample of iron is heated in air. It oxidizes to form a product with a mass of 2.205 g.
What is the empirical formula of the product?
Answer:
A 1.732 g sample of iron is heated in air. It oxidizes to form a product with a mass of 2.205 g. What is the empirical formula of the product? FeO 4. Caffeine is made of 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen by mass.
Explanation:
The empirical formula of the product formed by the reaction of iron and oxygen is FeO.
Let's consider the following generic chemical equation:
Fe + O₂ ⇄ FexOy
According to the law of conservation of mass, the sum of the masses of the reactants is equal to the sum of the masses of the products. The mass of O₂ that reacted, and remains in the oxide is:
[tex]mFe + mO_2 = mFexOy\\mO_2 = mFexOy - mFe = 2.205 g - 1.732 g = 0.473 g[/tex]
The oxide has 1.732 g of Fe and 0.473 g of oxygen and a total mass of 2.205 g. To determine the empirical formula, we need to calculate the percent composition.
[tex]\%Fe = \frac{mFe}{mFexOy} \times 100 \% = \frac{1.732 g}{2.205 g} \times 100 \% = 78.55\%[/tex]
[tex]\%O = \frac{mO}{mFexOy} \times 100 \% = \frac{0.473 g}{2.205 g} \times 100 \% = 21.45\%[/tex]
Now, we will divide each percentage by the atomic mass of the element.
[tex]Fe: 78.55/55.85 = 1.406\\O: 21.45/16.00 = 1.340[/tex]
Finally, we divide both numbers by the smallest one.
[tex]Fe: 1.406/1.340 \approx 1 \\O: 1.340/1.340 = 1[/tex]
The empirical formula of the product is FeO.
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two easy uses of mixture
Explanation:
it helps to make juices.
It helps to make concentrated acid into dilute acid.
Answer:
Explanation:
Here are a few more examples:
1. Smoke and fog (Smog)
2. Dirt and water (Mud)
list three factors that affect the rate of a chemical reaction
Answer: 1) temperature, 2) add a catalyst, and 3) concentrations
Explanation: A rise in temperature adds kinetic energy to the reactants, leading to more frequent, and energetic collisions, which will often accelerate the reaqction. A catalyst is an agent that helps the reaction move forward more quickly by offering a substrate that aids in orienting the reactants for more efficient reaction. A higher concentration increases the chances of collisons that result in products.
The solubility of solids______ when the temperature is increased.
A. increases
B. decreases
C. does not change
Oxide of nitrogen that is acidic
Answer:
Nitrogen oxides are used in the production of nitric acid, lacquers, dyes, and other chemicals. Nitrogen oxides are used in rocket fuels, in the nitrification of organic chemicals, and in the manufacture of explosives.
Explanation:
500kg, 42m, 675g, and 10m/s are all examples of what typed of data?b
500kg, 42m, 675g, and 10m/s are all examples of a: continuous data.
A numerical data can be defined as a data set that is expressed in numbers only or a data set consisting of numbers rather than words. A numerical data is also known as a quantitative data.
Generally, numerical data are classified into two (2) main categories and these are;
Discrete data: a discrete data is a data set in which the number of possible values are either finite or countable. Some examples are; the value of a fair die, number of pen in a box, number of eggs in a crate, etc.Continuous data: a continuous data is a data set that has infinitely many possible values and as such those values cannot be counted, which simply means they are uncountable. Any data (quantity) such as mass, height, volume, weight, density, velocity, length, pressure, temperature, speed, distance, time are generally classified as continuous data.In conclusion, mass (500 kg), height (42m), mass (675g), and speed (10m/s) are all examples of a: continuous data.
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A student was given a 2.850-g sample of a mixture of potassium nitrate and potassium bromide and was asked to find the percentage of each compound in the mixture. She dissolved the sample and added a solution that contained an excess of silver nitrate, AgNO3. The silver ion precipitated all of the bromide ion in the mixture as AgBr. It was filtered, dried, and weighed. Its mass was 1.740 g. What was the percentage of each compound in the mixture
Answer:
See explanation
Explanation:
The reaction occurs as follows;
KBr(aq) + AgNO3(aq) ----> AgBr(s) + KNO3(aq)
Number of moles of AgBr formed = mass /molar mass =1.740 g/187.77 g/mol = 0.0093 moles
From the reaction equation;
1 mole of KBr yields 1 mole of AgBr
Hence the number of moles of KBr reacted = 0.0093 moles
Mass of KBr present = 0.0093 moles × 119g/mol = 1.11 g
Mass of KNO3 = 2.850 g - 1.11 g = 1.74 g
Percentage of KBr = 1.11 g/2.850 g × 100 = 38.9%
Percentage of KNO3 = 1.74 g/2.850 g × 100 = 61.1%
which chloride is a coloured solid rtp
Answer:
sodium chloride
hope that helped :)
Answer:
Chlorine is a greenish yellow gas at room temperature and atmospheric pressure. ... yielding chlorine water, and from this solution a solid hydrate of ideal ...
Write the empirical formula for at least four ionic compounds that could be formed from the following ions: NO3, Pb^4+, NH4, SO4
Explanation:
here's the answer to your question
double arrow just mean that it's a reversible process, and the reaction can go back and forth.
The gases in a hair spray can are at a temperature of 27oC and a pressure of 30 lbs/in2. If the
gases in the can reach a pressure of 90 lbs/in2, the can will explode. To what temperature must
the gases be raised in order for the can to explode? Assume constant volume. Show your work.
Using Gay Lussac's Law
[tex]\boxed{\sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}}[/tex]
[tex]\\ \sf\longmapsto \dfrac{30}{27}=\dfrac{90}{T_1}[/tex]
[tex]\\ \sf\longmapsto T_1=\dfrac{90\times 27}{30}[/tex]
[tex]\\ \sf\longmapsto T_1=81°C[/tex]
Key Notes:-Gay Lussac's Law:-
It states that at constant volume (V),The pressure(P) of fixed amount of gas caries directly with its absolute temperature(T).
[tex]\\ \sf\longmapsto P\propto T[/tex]
[tex]\\ \sf\longmapsto \dfrac{P}{T}=Constant[/tex]
[tex]\\ \sf\longmapsto \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
[tex]\\ \sf\longmapsto P_1T_2=P_2T_1[/tex]
The final temperature of the gases with 90 lbs/in² is equal to 627°C assuming the volume is constant.
What is Gay Lussac's law?Gay-Lussac's law can be described as if the volume (V) of the gas remains constant then the pressure (P) is directly proportional to the absolute temperature (T) of the gas.
Gay Lussca's law in mathematical expression can be represented as:
P/T = k
It can be also represented as the pressure (P) being directly proportional to the temperature (T).
P ∝ T ( V of gas is constant)
or, P₁/T₁ = P₂/T₂
Given, the initial temperature of the gas, T₁ = 27°C = 27 + 273 = 300 K
The initial pressure of the gas, P₁ = 30 lbs/in²
The final pressure of the gas, P₂ = 90 lbs/in²
The final temperature of the gases in a hair spray can be determined as:
[tex]{\displaystyle \frac{P_1}{T_1} =\frac{P_2}{T_2}[/tex]
[tex]{\displaystyle T_2 =\frac{P_2\times T_1}{P_1}[/tex]
[tex]{\displaystyle T_2 =\frac{90\times 300}{30}[/tex]
T₂ = 900 K = 900 - 273
T₂ = 627°C
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16. The valency of sodium is +1 and that of chlorine is -1, why?
Answer:
It because ,sodium is a metal and chlorine is a non metal
what is the name of this organic molecule
Answer:
C2H4 Ethylene
Explanation:
Hope it helps! :)
Calculate the weight of CuO formed when 200g of Copper carbonate is heated.(Atomic weight of Copper-64,Carbon-12,Oxygen-16)
Answer:
129 g of CuO
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
CuCO₃ —> CuO + CO₂
Next, we shall determine the mass of CuCO₃ that decomposed and the mass of CuO produced from the balanced equation. This can be obtained as follow:
Molar mass of CuCO₃ = 64 + 12 + (16×3)
= 64 + 13 + 48
= 124 g/mol
Mass of CuCO₃ from the balanced equation = 1 × 124 = 124 g
Molar mass of CuO = 64 + 16
= 80 g/mol
Mass of CuO from the balanced equation = 1 × 80 = 80 g
SUMMARY:
From the balanced equation above,
124 g of CuCO₃ decomposed to produce 80 g of CuO.
Finally, we shall determine the mass of CuO produced by the decomposition of 200 g of CuCO₃. This can be obtained as follow:
From the balanced equation above,
124 g of CuCO₃ decomposed to produce 80 g of CuO.
Therefore, 200 g of CuCO₃ will decompose to produce
= (200 × 80)/124 = 129 g of CuO.
Thus, 129 g of CuO was obtained from the reaction.
Define force and speed
Force = The external energy that changes or tends to change the state of any body or object is called force.
Speed = The rate of distance is called speed.
Answer:
Force is a push or pull which changes or tend to change the position of a body.
The rate of change its position with time or magnitude is called speed.
A chemist sets up a chemical reaction but finds that none of the reactant molecules have the required activation energy. What is the result?
A.
Products will form with less energy input.
B.
No products will be formed.
C.
The products will form too quickly.
D.
Products will convert to reactants.
Answer:
B.
No products will be formed.
PLEASE HELP ASAP
Barney was a very inventive scientist and tried to perform the same experiments as those by famous scientists from long ago. One of the most challenging experiments was to roll out a very thin film of gold and put X-ray film in a circle around it. The difficult part was to get ahold of some radioactivity that he could shoot at the thin film for gold. One day, he ran into The Great Gazoo and told him his goal. The Great Gazoo said he had the perfect substance for him that was radioactive and should work. The element was named after him and had the symbol Gz. Barney quickly went back to his lab to run the experiment. What Barney noticed is that all the radioactive particles went through the gold film and none of them ricocheted back, but all went straight through the gold. Being puzzled, he quickly went to the lab to analyze this unknown radioactive substance. He found that the atomic number was 119, the mass number was 305. After a few more tests, Barney realized what was wrong with Gz. Your task is to figure out what was wrong with Gz by answering the following questions:
Whose experiment was Barney trying to imitate?
Where would Gz be located on Earth’s periodic table, column and row?
Give as many details on Gz that you could predict based on its location on the periodic table: type of chemical (metal, metalloid, or nonmetal), reactivity, ionization energy, electronegativity, and size of element.
What would the elements electron configuration end in?
Why did all the radioactive particles go straight through the gold film?
What would the daughter product be for Gz? Give all details for the atomic number, mass number, number of protons, neutrons and electrons.
If Gz had worked correctly, like Barney intended, what type of decay should Gz have had?
If Gz had worked correctly, what would the daughter product be? Give all details for the atomic number, mass number, number of protons, neutrons and electrons.
If Gz had worked correctly, what element would it become?
Answer:
a) Barney wants to repeat the rutheford experiment
b) the element will be in row 8 column 1 being an alkali metal
c) it should be a radioactive element, with a lot of mass
Explanation:
n this exercise they indicate that the particle Gz has atomic number 119 and atomic mass 305 amu, when reviewing the element periodicity table with this atomic number it has not yet been discovered, it should be in row 8 column 1 therefore it should be an alkali metal .
Therefore, it has only one electron in its last orbit.
a) Barney wants to repeat the rutheford experiment
b) the element will be in row 8 column 1 being an alkali metal
c) it should be a radioactive element, with a lot of mass
Which statements are true in regard to the VSEPR theory?
Select all that apply.
Molecules acquire a shape that results in the greatest charge.
Molecules acquire a shape that minimizes the repulsions of electron groups.
Molecules acquire a shape that maximizes the distance of electron groups.
Molecules acquire a shape that results in the lowest possible energy state.
The correct option is D. 2) Anti-bonding electrons or lone pairs. These lone pairs, and bonds helps to form the shape which keeps these electrons separate as possible.
Describe the formation of oxygen molecule
Answer:
oxygen molecule has two oxygen atom . Each O atom share 2 electrons to form two covalent bonds out of which one is sigma bond and other is pi bond . sigma bond is formed by axial overlap 2p atomic orbitals of oxygen and pi bond is formed of lateral overlap of 2p atomic orbitals of oxygen .
Sarah measures out 151 grams of SO2. How many moles is this? Express your answer to three significant figures.
Answer:
[tex]\boxed {\boxed {\sf 2.36 \ mol \ SO_2}}[/tex]
Explanation:
We are asked to convert grams to moles. We will use the molar mass and dimensional analysis to perform this conversion.
1. Molar MassThe molar mass is the mass of 1 mole of a substance. These values are found on the Periodic Table because they are equivalent to the atomic masses, but the units are grams per mole instead.
We are given a mass of sulfur dioxide (SO₂). Look up the molar masses of the individual elements.
Sulfur (S): 32.07 g/mol Oxygen (O): 15.999 g/molNotice that the formula of the compound contains a subscript. The subscript after O means there are 2 moles of oxygen in 1 mole of sulfur dioxide. We must multiply oxygen's molar mass before adding sulfur's.
O₂: 15.999 * 2 = 31.998 g/mol SO₂= 32.07 + 31.998 = 64.068 g/mol2. Convert Grams to Moles
Now we will use dimensional analysis to convert grams to moles. From the molar mass, we know there are 64.068 grams of sulfur dioxide per mole, so we can set up a ratio.
[tex]\frac {64.068 \ g \ SO_2} {1 \ mol \ SO_2}[/tex]
We are converting 151 grams to moles, so we multiply by this value.
[tex]151 \ g \ SO_2 *\frac {64.068 \ g \ SO_2} {1 \ mol \ SO_2}[/tex]
Flip the ratio so the units of grams of sulfur dioxide cancel.
[tex]151 \ g \ SO_2 *\frac {1 \ mol \ SO_2}{64.068 \ g \ SO_2}[/tex]
[tex]151 *\frac {1 \ mol \ SO_2}{64.068 }[/tex]
[tex]\frac {151}{64.068 } \ mol \ SO_2[/tex]
[tex]2.356870825 \ mol \ SO_2[/tex]
3. RoundThe original measurement of grams (151) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place. The 6 in the thousandth place tells us to round the 5 in the hundredth up to a 6.
[tex]2.36 \ mol \ SO_2[/tex]
151 grams of sulfur dioxide is approximately 2.36 moles of sulfur dioxide.
help me pls! plsssss
Answer:
Neutron, neutral subatomic particle that is a constituent of every atomic nucleus except ordinary hydrogen. It has no electric charge and a rest mass equal to 1.67493 × 10−27 kg—marginally greater than that of the proton but nearly 1,839 times greater than that of the electron.
write the balanced chemical equation for the following word equation. sodium+sulphate Acidsodium sulphate +hydrogen
Answer:
2NaOH+ H2SO4 → Na2SO4 + 2H2O
I HOPE ITS RIGHT IF NOT THEN SORRYHAVE A GREAT DAY :)
Answer:
Sodium+sulphate=Na2SO4
Acidsodium sulphate + hydrogen=Na2SO4+H2O
Hydrogen and oxygen combine in
the ratio of 1:8 by mass to form
water. What mass of oxygen gas
would be required to react
completely with 3 g of hydrogen
gas?
Answer:
hhshshhxujejushwhbwhsjs s hs
What are 5 uses of nitrogen?
Answer:
nitrogen is used in the production of 1) fertilisers 2) nitric acid 3) nylon 4) dyes and 5) explosives
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