Answer:
okay
Explanation:
9 . acidic
10. hydrogen
answer the following questions
11. Gold as a precious metal is used widely in making jewelry items. This metal is preferred over others for jewelry pieces for various reasons. One important reason for its popularity is that it does not react with atmospheric moisture and therefore, it does not rust.
12. corrosion is defined as rust it's due to humidity and moisture
13. Sulphur appears much below chlorine in the reactivity table and cannot displace chlorine from dilute HCl.
14. Highly conductive metal
Surpassed only by silver, copper is a highly conductive metal. This means electricity can pass through it with greater ease, making it ideal for use in electrical wires. Companies can use other conductive metals to create electrical wires.
15. Corrosion
Copper metal when exposed to air turns green in color due to corrosion. When the copper vessel is exposed to air in the rainy season, the metal reacts with gases, moisture, and atmospheric gases to form a mixture of copper carbonate and copper hydroxide. This gives a green color to the surface of the copper meta
16. Silicon
silicon is the backbone of the electronics industry. Because silicon is the reason for the fast development happened in the field of electronics. therefore, silicon is the backbone of electronics.
17. High chemical reactivity
Sodium is stored under kerosene because of its high chemical reactivity with almost all of the other elements (for example oxygen from the air which oxidizes it instantly). Kerosene and mineral oil are the only chemicals that make sodium inert. Usually, when Na reacts with a solvent it liberates hydrogen gas from its composition.
18. Metal oxides are oxides of metals. Nonmetal oxides are oxides of nonmetals. The main difference between metal oxides and nonmetal oxides is that metal oxides are basic compounds whereas nonmetal oxides are acidic compounds.
19. Silver is more likely to tarnish near a petroleum refinery than in a place far away from it because when silver reacts with petroleum or hydrogen sulfide present in it as a pollutant in the air, it starts forming a black coating of silver sulfide.
20. A noble metal is ordinarily regarded as a metallic chemical element that is generally resistant to corrosion and is usually found in nature in its raw form. Gold, platinum, and the other platinum group metals (ruthenium, rhodium, palladium, osmium, iridium) are most often so classified. Silver, copper, and mercury are less often to sometimes included as noble metals although each of these usually occurs in nature combined with sulfur.
Corrosion may be regarded as the destruction of metal by:
Electrochemical action
Hydroelectric action
Electromechanical action
All of the above
Question 18 of 32
What is a covalent bond?
OA. A bond in which molecules share electrons
OB. A bond in which atoms share electrons
C. A bond between ions of the same charge
Answer: A. A bond in which molecules share electrons
Which of the following is a correct statement regarding the free energy?
It is energy available to create bonds.
It always has the same value.
It is stored between atoms.
It is known as kinetic energy.
Answer:
A
Explanation:
One donut contains 350 kcal. Convert this to calories and joules
350 Kcal is equals to 350000 calorie and 1464400 Joule.
How to calculate energy content in food ?The equation for calculating the energy content of a food source via calorimetry is as follows: Energy (joules) = Mass of water (g) × 4.2 (J/gºC) × Temperature increase (ºC)
1 Kcal = 1000 calorie
Therefore,
35 Kcal = 350 x 1000
= 350000 calorie
Now,
1 calorie = 4.184 joule
Therefore,
35000 calorie = 350000 x 4.184
= 1464400 joule
Hence, 350 Kcal is equals to 350000 calorie and 1464400 Joule.
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At a certain temperature this reaction follows first-order kinetics with a rate constant of 0.086 s^-1:
2H3PO4(aq)=P2O5(aq)+3H2O(aq)
Suppose a vessel contains H3PO4 at a concentration of 1.27 M . Calculate how long it takes for the concentration of H3PO4 to decrease to 7.0% of its initial value. You may assume no other reaction is important.
Round your answer to 2 significant digits.
Please, need this ASAP
It takes 31 s for 1.27 M H₃PO₄ to decrease its concentration to 7.0% of its initial value following first-order kinetics.
What is first-order kinetics?First-order kinetics occur when a constant proportion of a reactant disappears per unit time.
Let's consider the following first-order kinetics reaction with a rate constant k = 0.086 s⁻¹.
2 H₃PO₄(aq) = P₂O₅(aq) + 3 H₂O(aq)
Given the initial concentation is [H₃PO₄]₀ = 1.27 M, the concentration representing 7.0% of this value is:
[H₃PO₄] = 7.0% × 1.27 M = 0.089 M
We can calculate the time elapsed (t) using the following expression.
ln ([H₃PO₄]/[H₃PO₄]₀) = - k × t
ln (0.089 M/1.27 M) = - 0.086 s⁻¹ × t
t = 31 s
It takes 31 s for 1.27 M H₃PO₄ to decrease its concentration to 7.0% of its initial value following first-order kinetics.
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A cubic meter of air was sampled at 1.0 ATM and 40 C.
An ion chromatographic analysis of that sample found it to contain 12 micrograms of NO2.
How many ppb of NO2 is in the air?
The amount of nitrogen oxide in the air sample is determined as 7.01 ppb.
Amount of Nitrogen oxide in the air
The amount of Nitrogen oxide (NO2) in the air in parts per billion (ppb) is calculated as follows;
12 micrograms of NO2 = 12 μg = 12 x 10⁻⁶ g
PV = nRT
V = nRT/P
Where;
V is volume of NO2 gasn is number of moles of NO2 gasT is temperature = 40 C = 313 Kn = m/M
M = molar mass of NO2 = 46
n = 12 x 10⁻⁶/46
n = 2.73 x 10⁻⁷ mole
V = (2.73 x 10⁻⁷ x 0.082057 x 313)/(1)
V = 7.01 x 10⁻⁶ L
V = 7.01 x 10⁻⁹ m³
Amount of NO2 In parts per billion= (Volume of NO2)/(volume of air) x 10⁹
= (7.01 x 10⁻⁹)/(1) x 10⁹
= 7.01 ppb
Thus, the amount of nitrogen oxide in the air sample is determined as 7.01 ppb.
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Which of the following would cause an increase in the magnetic force
between two magnets?
A. Decreasing the separation between the two magnets
B. Increasing the separation between the two magnets
C. Decreasing the amount of excess charge on the first magnet
D. Increasing the amount of excess charge on the first magnet
Decreasing the separation between the two magnets will result in increase in the magnetic force between two magnets.
What is a Magnet?This is referred to a substance which produces magnetic field and result in the attraction and repulsion of certain types of things.
Increase in the separation will reduce the magnetic force and vice versa which is why option A was chosen.
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Complete combustion of 8.60 g of a hydrocarbon produced 26.5 g of CO2 and 12.2 g of H2O. What is the empirical formula for the hydrocarbon?
The empirical formula of the hydrocarbon is [tex]C_2H_3[/tex] if combustion of 8.60 g of a hydrocarbon produced 26.5 g of [tex]CO_2[/tex] and 12.2 g of [tex]H_2O[/tex].
What is an empirical formula?A chemical formula showing the simplest ratio of elements in a compound rather than the total number of atoms in the molecule [tex]CH_2O[/tex] is the empirical formula for glucose.
1 mole of carbon dioxide contains a mass of 44 g, out of which 12 g are carbon.
Hence, in this case the mass of carbon in 8.46 g of [tex]CO_2[/tex]:
([tex]\frac{12}{44}[/tex]) × 8.46 = 2.3073 g
1 mole of water contains 18 g, out of which 2 g is hydrogen;
Therefore, 2.6 g of water contains;
([tex]\frac{2}{18}[/tex] × 2.6 = 0.2889 g of hydrogen.
Therefore, with the amount of carbon and hydrogen from the hydrocarbon, we can calculate the empirical formula.
We first calculate the number of moles of each,
Carbon = [tex]\frac{2.3073}{12}[/tex] = 0.1923 moles
Hydrogen = [tex]\frac{0.2889}{1}[/tex]= 0.2889 moles
Then, we calculate the ratio of Carbon to hydrogen by dividing by the smallest number value;
Carbon : Hydrogen
[tex]\frac{0.1923}{0.1923}[/tex] : [tex]\frac{0.2889}{0.1923}[/tex]
1 : 1.5
(1 : 1.5) 2
= 2 : 3
Hence, the empirical formula of the hydrocarbon is [tex]C_2H_3[/tex].
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What is the primary purpose of a rate law?
Oto determine if a chemical reaction will be exothermic or endothermic
O to determine the amount of product that is formed from the concentration of reactants
O to show the relationship between the concentration of reactants and the reaction rate
O to show a relationship between the amounts of gas that can dissolve into a liquid
The rate law uses the molar concentrations of reactants to determine the reaction rate. Hence, option (C) is the correct option
What is rate law ?A rate law shows how the rate of a chemical reaction depends on reactant concentration.
For a reaction such as aA → products, the rate law generally has the form
rate = k[A]ⁿ,
where,
k is a proportionality constant called the rate constantn is the order of the reaction with respect to A.Typically, increased concentrations of reactants increases the speed of the reaction, because there are more molecules colliding and reacting with each other.
Hence , The rate law uses the molar concentrations of reactants to determine the reaction rate. Hence, option (C) is the correct option
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What are the rows of the periodic table called?
A. Periods
B. Elements
C. Atoms
D. Groups
Answer:
i believe its called A. periods
What is the percent yield for the reaction below when
705.0 g SO2 and 80.0 g 0₂ produce 586.0 g SO3?
2SO2(g) + O2(g) → 2SO3(g)
The percent yield would be 68.3%
Percent yieldThis is given as:
Percent yield = yield/theoretical yield x 100%
From the equation:
[tex]2SO_2(g) + O_2(g) -- > 2SO_3(g)[/tex]
The mole ratio of the reactants is 2;1
Mole of 705 g SO2 = 705/64 = 11.02 moles
Mole of 80 g O2 = 80/32 = 2.5 moles
O2 is limiting.
Mole ratio of O2 and SO3 = 1:2
Mole equivalent of SO3 = 2.5 x 2 = 5.0 moles
Mass of 5 moles SO3 = 5 x 80 = 400 grams
Percent yield = 400/586 = 68.3%
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If winds blow against a mountain from the south, then on which slope would you find the least precipitation?
The northern slope will have the least precipitation if winds blow against a mountain from the south.
What is Slope?This is referred to as the degree of steepness on a surface such as rocky areas etc.
When wind blows on the southern part of a mountains, it gets stuck which is why the northern slope have the least precipitation.
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Which statement best explains why gneiss is composed of layers but there are no layers in granite?
Gneiss is a sedimentary rock and granite is a metamorphic rock.
Gneiss is a metamorphic rock and granite is a sedimentary rock.
Granite is formed due to the slow cooling of magma below Earth's surface and gneiss is formed due to metamorphosis.
Granite is formed due to the accumulation of sediments and gneiss is typically formed due to intense heat and pressure.
Gneiss is a sedimentary rock and granite is a metamorphic rock. That is option A.
What are rocks?Rocks are geological hard materials that are made up of various types which include:
Sedimentary rocks: These are rocks that made up of various layers formed from sediments. Example is the gnesis.Metamorphic rocks: These are rocks that are form from pre existing rocks that undergoes some transformation. Example is graniteTherefore, Gneiss is a sedimentary rock and granite is a metamorphic rock.
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Answer:
C
Granite is formed due to the slow cooling of magma below Earth's surface and gneiss is formed due to metamorphosis.
Explanation:
I took the test!
3-chloropropylamine what is?
Answer:
a chemical compound
how many moles of FeCl3 are produced when 3.0 mole.of Fe react eith excess Cl2 gas?
What is the molarity of a solution made by dissolving 3.09 moles of NaCl in 1.50 L of solution?
Answer:
2.06M NaCl
Explanation:
Molarity is defined as a ratio of moles of the solute (the substance you're dissolving) to Liters of solution (the volume of the finished solution). It uses the letter capital M as an abbreviation for the unit.
We're given values for both numbers (with the correct units already), so substitute, and calculate the number part:
[tex]\dfrac{n_{solute}}{V_{solution}}=\dfrac{3.09 [\text{mol NaCl}]}{1.50 [\text{L solution}]}=2.06\dfrac{[\text{mol NaCl}]}{[\text{L solution}]}=2.06[\text{M NaCl}][/tex]
What is the molar concentration of Zn2+ ions in a solution, if the electrode potential value is 59mV less than the standard electrode potential value at 298 K?
Molar concentration of Zn2+ions in a solution is 3.481 mol/lit
The electrode potential value is 59mV
Temperature=298k
What is electrode potential?
It is a force of galvanic cell. basically it is the difference between an electrolyte and electrode.equation formed- Zn → Zn2+ + 2e
from Nernst equation-
E=E cell - 0.059 log [Zn2+]
[zn2+]=3.481 mol/lit
hence, Molar concentration of Zn2+ions in a solution is 3.481 mol/lit
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A corn plant has been genetically engineered. It produces pollen that can make its own toxins. These toxins protect the corn plant against pests. What is a likely impact on the environment around the corn plant?
Bird and butterfly populations around the area may increase.
The concentration of pesticides in a nearby lake would increase.
Newer strains of pesticide-resistant pests may develop.
The carbon dioxide level would increase in the area.
Answer:
I think the answer is "newer strains of pesticide - resistant pests may develop" as I learnt in Biology, but I'm not sure as I don't know anything about corn plants.
Explanation:
Answer:
newer strains of pesticide
Explanation:
Avogadro's number is the number of atoms or molecules in one mole of any substance. In other words, a mole is 6.02X1023 of some chemical unit. The size of the chemical unit does not change Avogadro’s number. An analogy can be made using eggs. You can buy small, medium, or large eggs. The size of the eggs doesn’t affect how many eggs are in one dozen. Similarly, the size of the representative particle doesn’t affect how many are in one mole. Describe your own analogy to show the relationship between moles and the size of representative particles.
Calculate the mass of pure sodium chloride will yield enough hydrogen chloride gas to tralize 25 cm² of 0.5 M potassium trioxo- bonate(IV) solution. NACI=58.5, HC1 = 36.5, K,CO, = 138)
In the reaction below, 1.000 × 103 g LiOH is combined with 8.80 × 102 g CO2. The reaction produces 3.25 × 102 g H2O in an experiment.
CO2 + 2LiOH → Li2CO3 + H2O
theoretical yield
Answer:
CO2
Explanation:
100% CORRECT ON EDGE
The mass of water produced when 1.000 × 10³ g of LiOH is combined with 8.80 × 10² g CO₂ is 3.25 × 10² g H₂O.
What is mass?Mass is defined as a dimensionless number used to describe the mass of a particle or item. The kilogram is the International System's (SI) preferred unit of mass (kg). Atoms make up everyday matter. A majority of an atom's mass is contained in its nucleus.
It is a neutralization process when lithium hydroxide and carbon dioxide combine to form water and lithium carbonate.
The reaction is [tex]\rm CO_2 + 2LiOH \rightarrow Li_2CO_3 + H_2O[/tex]
Neutralization reaction is defined as an acid and base reaction that produces an ionic molecule and potentially water.
Thus, the mass of water produced when 1.000 × 10³ g of LiOH is combined with 8.80 × 10² g CO₂ is 3.25 × 10² g H₂O.
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Which of the following is the electron configuration of an atom in the ground state?
(a) 1s2 2s1
(b) 1s2 2s2 2p5 3s2
(c) 1s2 2s1 2p6
(d) 1s1 2s2
Answer:
(a) 1s2 2s1
Explanation:
Electron configurations of atoms are in their ground state when the electrons completely fill each orbital before starting to fill the next orbital.
Understanding the notationIt's important to know how to read and interpret the notation.
For example, the first part of option (a) says "1s2"
The "1" means the first level or shellThe "s" means in an s-orbitalThe "2" means there are 2 electrons in that orbitalOther things to know about electron orbitalsIt important to know which orbitals are in each shell:
In level 1, there is only an s-orbitalIn level 2, there is an s-orbital and a p-orbitalin level 3, there is an s-orbital, a p-orbital, and a d-orbital (things get a little tricky when the d-orbitals get involved, but this problem is checking on the basic concept -- not the higher level trickery)So, it's also important to know how many electrons can be in each orbital in order to know if they are full or not. The electrons should fill up these orbitals for each level, in this order:
s-orbitals can hold 2p-orbitals can hold 6d-orbitals can hold 10 (but again, that's beyond the scope of this problem)Examining how the electrons are filling the orbitalsFor option (a):
the 1s orbital is filled with 2, andthe 2s orbital has a single electron in it with no other orbitals involved.This is in it's ground state.
For option (b):
the 1s orbital is filled with 2, the 2s orbital is filled with 2,the 2p orbital has 5 (short of a full 6), andthe 3s orbital has a single electron in it.Because the 3s orbital has an electron, but the lower 2p before it isn't full. This is NOT in it's ground state.
For option (c):
the 1s orbital is filled with 2, the 2s orbital has 1 (short of a full 2), andthe 2p orbital is filled with 6Although the 2p orbital is full, since the 2s orbital before it was not yet full, this is NOT in it's ground state.
For option (d):
the 1s orbital has 1 (short of a full 2), andthe 2s orbital is filled with 2Again, despite that the final orbital (in this case, the 2s orbital), is full, since the 1s orbital before it was not yet full, this is NOT in it's ground state.
A group of students measure the length of a pencil using a metric ruler. The pencil has a known length of 14.2 cm. They record the following measurements: 13.7 cm, 13.6 cm, and 13.7 cm. What is the best way to describe their data?
a. Accurate, but not precise
c. BOTH accurate and precise
b. Precise, but not accurate
d. NEITHER accurate nor precise
Answer:
Neither accurate not precise
describe 2 ways of salting out proteins
The phenomenon known as "salting-out" occurs at very high ionic strengths, when protein solubility declines as ionic strength rises. As a result, salting out may be used to segregate proteins according to how soluble they are in salt solutions.
Because large levels of sodium chloride disturb the bonds and structure of the active site, the rate of enzyme activity will gradually decrease as the concentration of sodium chloride rises. As a result, some of the active sites get denaturized and the starch loses its ability to attach to them. As more enzymes get denatured and eventually cease to function, enzyme activity will steadily wane.
Describe the characteristics that identify a sample of matter as being a substance.
No matter how big or little a material is, its properties remain the same. Size, form, color, and mass are the qualities that distinguish a material from non-substances. All of these qualities, including size, shape, color, and mass, can be seen and measured. Some characteristics are physical, while others are chemical. Physical characteristics include mass, volume, density, and color. Viscosity and solubility are examples of chemical qualities.
Which element has properties most like Mg?
Answer:
The elements which are in the group
Magnesium reacts with sulfuric acid according to the fol-
lowing equation. How many moles of H₂ are produced by
the complete reaction of 230. mg of Mg with sulfuric acid?
Mg(s) + H₂SO (aq) →
MgSO₂(aq) + H₂(g)
Answer:
The moles of H2 is 230-two hundred and thirty
Predict the nature of the indicated
covalent bond.
non-polar
Explanation :
Hydrogen and carbon have similar electronegativity values, so the C—H bond is not normally considered a polar covalent bond.
A hydrocarbon contains 87,8% carbon and
12.2% hydrogen by mass. Its empirical
formula is?
C= 87.8 : 12 = 7.316
H= 12.2 : 1 = 12.2
C : H = 1 : 1.667 = 3 : 5
C₃H₅
Given the following equation, how many grams of PbCO3 will dissolve when 2.50 L of 1.50 M H+ is added to 3.00 g of PbCO3?
Given
PbCO3(s) + 2H+(aq) = Pb^2(aq)+ +H2O (l)+ CO2(g)