Answer:
The two main types of chemical bonds are covalent bonds and ionic bonds.Explanation:
Ionic bonds are formed by the electrostatic attraction between a positive ion (named cation) and a negative ion (named anion).
A cation is formed when an atom donates one or more electrons from its valence shell, while an anion is formed when an atom accepts one or more electrons.
The most classical example of a ionic bond is that of sodium chloride: sodium (Na) is a metal with one valence electron, and chlorine (Cl) is a nonmetal with 7 valence electrons. Then, sodium releases its valence electron (forming the cation Na⁺), which is accepted by chlorine (forming the anion chloride, Cl⁻). These two ions with opposite charge are bonded by the attractive electrostatic force.
Covalent bonds are the result of sharing valence electrons. In this case, the atoms do not exchange (donate/accept) electrons but share them; meaning that the shared electrons belong to the outermost energy level of the two atoms, now bonded by the covalent bond.
Furthermore, the covalent bond may be polar or non-polar. A polar covalent bond is formed when the two atoms have different electronegativities, because in such case one atom pulls the electrons harder than the other, resulting in an uneven distribution of the charge, i.e. forming a dipole.
in order to protect aquifers near landfills, material is placed under the soil to prevent pollution. which following property must the protective material possess?
a) high porosity
b) low permeability
c) high reflectivity
d) low conductivity
Answer:
b) low permeability
Explanation:
In landfills, materials with low porosity and low permeability are often placed under the soil to prevent pollution.
Permeability deals with the inter-connectivity of pore spaces within a rock or soil unit. Permeability aids the movement or transmission of fluids within the pores of a rock. When pore spaces are interconnected, permeability increases. This would eventually lead to leaking of dissolved materials from the landfill into the ground water system and can contaminate the environment.
When 50 ml (50 g) of 1.00 m hcl at 22oc is added to 50 ml (50 g) of 1.00 m naoh at 22oc in a coffee cup calorimeter, the temperature increases to 28.87oc. how much heat is produced by the reaction between hcl and naoh? (the specific heat of the solution produced is 4.18 j/goc)?
Answer:
[tex]\boxed{\text{2700 J}}[/tex]
Explanation:
HCl + NaOH ⟶ NaCl + H₂O
There are two energy flows in this reaction.
Heat of reaction + heat to warm water = 0
q₁ + q₂ = 0
q₁ + mCΔT = 0
Data:
m(HCl) = 50 g
m(NaOH) = 50 g
T₁ = 22 °C
T₂ = 28.87 °C
C = 4.18 J·°C⁻¹g⁻¹
Calculations:
m = 50 + 50 = 100 g
ΔT = 28.87 – 22 = 6.9 °C
q₂ = 100 × 4.18 × 6.9 = 2900 J
q₁ + 2900 = 0
q₁ = -2900 J
The negative sign tells us that the reaction produced heat.
The reaction produced [tex]\boxed{\textbf{2900 J}}[/tex].
The reaction between HCl and NaOH in the situation described produced 2.87 kJ of heat.
Explanation:The question is asking how much heat is produced by the reaction between 1.00 M hydrochloric acid (HCl) and 1.00 M sodium hydroxide (NaOH) in a coffee cup calorimeter when the initial temperature is 22ºC and the final temperature is 28.87ºC. The heat released in a chemical reaction can be calculated from the formula q = mcΔT, where q is heat, m is mass, c is specific heat, and ΔT is the change in temperature. In this case, the mass of the solution is 100g (50g HCl + 50g NaOH), the specific heat of the solution is given as 4.18 J/gºC, and the change in temperature is 28.87ºC - 22ºC = 6.87ºC.
Applying the numbers in the formula we get:
q = 100g * 4.18 J/gºC * 6.87ºC = 2872.6 J
Since the question requires the answer in kJ, we divide the result by 1000: Q = 2.87 kJ. The reaction between HCl and NaOH in the calorimeter produced 2.87 kJ of heat.
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Why does alkali elements react vigorously with water?
Answer:
Explanation:
Because the alkali metal is really willing to give up its electron much more so than Hydrogen.
The redox reaction looks like this
K ===> K+ + 1 e- The reduction vo is very high which means that the K really does want to give up that electron.
2H+ +2e- ====> H2 The oxidation vo is almost 0 but the Hydrogen is the perfect recipient for the 2 electrons.
Which compound can act as both a Brønsted-Lowry acid and a Brønsted-Lowry base?
a. water
b. oxygen
c. sodium hydroxide
d. hydrochloric acid
An ionic bond can be formed when one or more electrons are 1) equally shared by two atoms 2) unequally shared by two atoms 3) transferred from the nucleus of one atom to the nucleus of another atom 4) transferred from the valence shell of one atom to the valence shell of another atom
Answer:
4) transferred from the valence shell of one atom to the valence shell of another atom
Explanation:
Electrons are located outside of the nucleus which contains the protons and the neutrons.
For bonds to form, valence electrons located in the outermost shell electrons are involved. These are the valence electrons. These outer shell electrons can be shared or transferred between two combining atoms to form stable atoms.
In ionic bonds, the electrons are transferred from one specie to another. The atom that loses the electrons becomes positively charged and the receiving atom becomes negatively charged. This is the crux of ionic bonds.
What is the concentration of a solution that has a volume of 2.5L and contains exactly 2.125 moles of calcium phosphate
Answer:
0.85 mol/L.
Explanation:
Molarity is defined as the no. of moles of solute dissolved in a liter of the solution.M = (no. of moles of solute)/(Volume of the solution (L))
no. of moles of calcium phosphate = 2.125 mol.
Volume of the solution = 2.5 L.
∴ M of calcium phosphate = (2.125 mol)/(2.5 L) = 0.85 mol/L.
What is the pH of a 1.0 molar solution of HCl?
Answer:
0.
Explanation:
For 1.0 M HCl:[H⁺] = 1.0 M.
∵ pH = - log[H⁺]
∴ pH = - log(1.0 M) = 0.
Final answer:
The pH of a 1.0 molar solution of HCl is 0.
Explanation:
The pH of a 1.0 molar solution of HCl can be calculated using the formula pH = -log[H3O+]. Since HCl is a strong acid, it completely ionizes in water to form H3O+ ions. Therefore, the hydrogen ion concentration is equal to the molar concentration of HCl.
Thus, the pH of a 1.0 molar solution of HCl would be -log(1.0) = 0.
Therefore, the pH of the solution is 0.
Read the information in the table below:
Reaction
A Energy to break bonds is more than energy release to form bonds
B Energy to break bonds is less than energy release to form bonds
Which type of reaction is represented by B?
Endothermic reaction
Exothermic reaction
Reaction between liquids
Reaction between solids
Exothermic Reactions
Answer:
Reaction B is exothermic
Explanation:
From the context of thermodynamics, chemical reactions can be broadly classified as endothermic and exothermic reactions.
Endothermic reactions involve absorption of energy and show a positive value for the reaction enthalpy i.e. ΔH is positive. In contrast, exothermic reactions are accompanied by the release of energy and show a negative value for the enthalpy change i.e. ΔH is negative.
In a given chemical reaction energy is required to break bonds and it is released during the formation of new bonds.
The Reaction B is such that, the energy required to break bonds is less than energy released during formation bonds. Therefore, since there is a net release of energy, the reaction is exothermic.
Petroleum, natural gas, and coal are the largest sources of _____.
1. oxygen compounds
2. carbon compounds
3. nitrogen compounds
4. silicon compounds
Answer:
The answer would be 2. carbon compounds.
Hope this helps!
Brainliest?
Calculate the percentage yield for the reaction represented by the equation CH4 + 2O2 ? 2H2O + CO2 when 1000 g of CH2 react with excess O2 to produce 2300 g of CO2.
Answer:
83.64%.
Explanation:
∵ The percent yield = (actual yield/theoretical yield)*100.
actual yield of CO₂ = 2300 g.
We need to find the theoretical yield of CO₂:For the reaction:
CH₄ + 2O₂ → 2H₂O + CO₂,
1.0 mol of CH₄ react with 2 mol of O₂ to produce 2 mol of H₂O and 1.0 mol of CO₂.
Firstly, we need to calculate the no. of moles of 1000 g of CH₄ using the relation:no. of moles of CH₄ = mass/molar mass = (1000 g)/(16.0 g/mol) = 62.5 mol.
Using cross-multiplication:
1.0 mol of CH₄ produces → 1.0 mol of CO₂, from stichiometry.
∴ 62.5 mol of CH₄ produces → 62.5 mol of CO₂.
We can calculate the theoretical yield of carbon dioxide gas using the relation:∴ The theoretical yield of CO₂ gas = n*molar mass = (62.5 mol)(44.0 g/mol) = 2750 g.
∵ The percent yield = (actual yield/theoretical yield)*100.
actual yield = 2300 g, theoretical yield = 2750 g.
∴ the percent yield = (2300 g/2750 g)*100 = 83.64%.
The study of chemicals and bonds is called chemistry. There are two types of metals and these are metals and nonmetals.
The correct answer to the question is 83.64.
What is a combination reaction?The formation of the new compound by joining the two different elements is called a combination reaction.
According to the question
The percent yield = (actual yield/theoretical yield)*100.
Hence, the actual yield of CO₂ = 2300 g.
The reaction is as follows: - [tex]CH_4 + 2O_2 --- > 2H_2O + CO_2[/tex]
1.0 moles of CH₄ reacts with 2 moles of O₂ to produce 2 moles of H₂O and 1.0 moles of CO₂. Firstly, we need to calculate the no. of moles of 1000 g of CH₄ using the relation:
no. of moles of CH₄ = mass/molar mass =
[tex]\frac{(1000 g)}{(16.0 g/mol)} = 62.5 mol.[/tex]
Using cross-multiplication:
1.0 mole of CH₄ produces ---> 1.0 mole of CO₂, from stoichiometry.62.5 moles of CH₄ produces ---> 62.5 moles of CO₂.We can calculate the theoretical yield of carbon dioxide gas using the relation:
The theoretical yield of CO₂ gas = n*molar mass =[tex](62.5 mol)(44.0 g/mol) = 2750 g.[/tex]
∵ The percent yield = (actual yield/theoretical yield)*100.
Actual yield = 2300 g, Theoretical yield = 2750 g.The percent yield = [tex](2300 g/2750 g)*100 = 83.64%[/tex]%
Hence, the correct answer is 83.64.
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NEED ANSWERED ASAP! 50 POINTS!!!!!!
For the reaction below, describe the temperature and pressure conditions that would produce the highest yield for the forward reaction. Explain your answer in terms of Le Châtelier's principle. (2 points)
N2(g) + 3H2(g) ---><--- 2NH3(g) delta H = -92 kJ/mol
Answer:
"CO(g) + 2H2 (g) <---> CH3OH (g) and that the reaction is exothermic (the delta H value is negative). The reaction is exothermic, so lowering the temperature will shift the equilibrium toward the right. Since the reaction uses 3 moles of gas to form 1 mole of gas, increasing the pressure will shift the reaction toward the right. So, low temperature and high pressure will produce the highest yield.
Explain how the sizeof particles, catalyst,concerntration and temperature of the substance can affect the rate of reaction?
Answer:
Look at explanation
Explanation:
Size of particles increases, rate of reaction decreases, and vise versa
Catalyst causes the rate of reaction to increase
Concentration increases, rate of reaction increases, and vise versa
Temperature increases, rate of reaction increases, and vise versa
What is the relative rate of effusion for hydrogen iodide (128 g/mol) compared to gaseous hydrochloric acid (36.5 g/mol)
This question is hard but I found the answer from merit nation
What do elements in the same family generally have similar properties?
Answer:
Explanation:
Elements in the same family belong to the same group.
A group on the periodic table is the vertical arrangement of elements. Elements in the same group have the same amount of valence electrons in their outermost shell. We know that the valency of an element dictates its chemical properties. In group I for example, elements here have just a valence electron, this makes group I elements readily lose their electrons to achieve a noble configuration.
Physical properties to an extent also varies and progresses down the group steadily.
This is why elements in the same family are said to generally have similar properties
Elements in the same family or group on the periodic table generally have similar properties, such as reactivity and the types of compounds they form, because they have the same number of valence electrons. For example, the halogens in Group 17 and the alkali metals in Group 1 have similar properties due to their shared valence electron configurations.
Explanation:The elements in the same family or group on the periodic table generally have similar properties because they have the same number and distribution of electrons in their valence shells. These valence electrons determine how elements interact with other substances and react chemically. For example, elements in the same family tend to have similar reactivity and form similar types of compounds.
For instance, the halogens (fluorine, chlorine, bromine, iodine, and astatine) are all located in Group 17 of the periodic table and have similar properties because they all have seven valence electrons. They are highly reactive nonmetals that have a tendency to gain one electron to achieve a stable electron configuration.
Another example is the alkali metals (lithium, sodium, potassium, etc.), which are found in Group 1. They all have one valence electron and are highly reactive metals that readily lose this electron to form a +1 cation.
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Which of the following atoms has a full outer shell?
A. Ca
B. Li−1
C. N−2
D. Mg+2
Magnesium has a full outer shell because it says +2 for Mg, which means it loses 2 electrons. It leaves Mg with an outer shell of 8 electrons, which is a full valence shell.
Mg+2 among the following has the full outer shell , therefore option (d) is correct.
What do you mean by outer shell ?A full outer shell is known as the noble gas configuration where the outer shell of an atom is energetically stable and contains 8 outer electrons .
It belongs to a group called the noble gases. When the outer shell has the maximum number of electrons, the electron shells. are said to be full.
The inner shells of an atom are always full. If the outer shell of an atom has less than , its maximum number of electrons then it will not be stable.
Elements with complete outer shell are Helium , Neon, Argon, Krypton , Xenon , Radon .
Mg+2 among the following has the full outer shell ,hence option (d) is correct .
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