Calculate the average atomic mass for element X(please help)
Answer:
Wt Avg At Mass = 39.0229 amu
Explanation:
The Weight Average Atomic Mass in atomic mass units (amu) is the sum of the Weight Average Mass contributions of each isotopic mass. That is,
Wt. Avg. At. Mass (amu) = ∑ Wt. Avg. Contributions of each isotopic mass
Wt. Avg. Contribution = fractional abundance x isotopic mass(amu)
For this problem data:
Isotope %Abundance fractional Isotopic Wt Avg Isotopic
abundance mass(amu) Contribution (amu)
1 9.67% 0.0967 38 3.6746 amu
2 78.68% 0.7868 39 30.6852 amu
3 11.34% 0.1134 40 4.5360 amu
4 0.31% 0.0031 41 0.1271 amu
________________________________________________________
Wt. Avg. Atomic Mass (amu) = ∑ Wt. Avg. Contributions = 39.0229 amu
I need answers to question 1,2,3
Answer:
1. 0.125 mole
2. 42.5 g
3. 0.61 mole
Explanation:
1. Determination of the number of mole of NaOH.
Mass of NaOH = 5 g
Molar mass of NaOH = 23 + 16 + 1
= 40 g/mol
Mole of NaOH =?
Mole = mass /molar mass
Mole of NaOH = 5/40
Mole NaOH = 0.125 mole
2. Determination of the mass of NH₃.
Mole of NH₃ = 2.5 moles
Molar mass of NH₃ = 14 + (3×1)
= 14 + 3
= 17 g/mol
Mass of NH₃ =?
Mass = mole × molar mass
Mass of NH₃ = 2.5 × 17
Mass of NH₃ = 42.5 g
3. Determination of the number of mole of Ca(NO₃)₂.
Mass of Ca(NO₃)₂ = 100 g
Molar mass of Ca(NO₃)₂ = 40 + 2[14 + (3×16)]
= 40 + 2[14 + 48]
= 40 + 2[62]
= 40 + 124
= 164 g/mol
Mole of Ca(NO₃)₂ =?
Mole = mass /molar mass
Mole of Ca(NO₃)₂ = 100 / 164
Mole of Ca(NO₃)₂ = 0.61 mole
A substance x has a mass of 0,20g and molecular mass of 40g/mol.Find the number of moles of substance x.
Answer:
0,005
Explanation:
number of moles=mass/molecular mass
therefore it's going to be 0,20g over 40g/mol
which is 0,20g/40g/mol... grams and grams will cancel making the answer 0,005moles
Boiling the solution causes the equilibrium in the following reaction to shift to the ________. HCO3- H3O --> H2CO3 H2O
Answer:
Right
Explanation:
The reaction of bicarbonate ion with acid is shown in the following equation;
HCO3- + H3O --> H2CO3 + H2O
This reaction is endothermic. This implies that energy must be absorbed from the surrounding as the reaction progresses.
Hence, when the solution is boiled, energy is supplied to the system in the form of heat and the forward reaction is favoured hence the equilibrium shifts to the right.
what is one cause of long-lasting climate change?
Answer: Carbon dioxide is the main cause of human-induced climate change. ... Some, such as nitrous oxide, are long-lived greenhouse gases like carbon dioxide, and so contribute to long-term climate change. Other substances have shorter atmospheric lifetimes because they are removed fairly quickly from the atmosphere.
hope it helps
Help me please I really need this tomorrow
9.D
10.A
11.C
12.B
13.D
14.C
15.A
16.A
18.C
The reversible reaction, 4HCl(g) + Si (s) ⇌ SiCl4 (l) + 2H2 (g) , would be classified as a ______________ reaction.
exothermic
endothermic
homogeneous
heterogeneous
Answer:
endothermic
Explanation:
endothermic reactions absorb heat from their surroundings, in this reaction the reactants are gas and solid and the products are liquid and gas, implying heat was absorbed to turn a solid to a liquid.
3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?
Answer:
Calculate the geometric average return earned by an investor over three years if she earned 6% in the first year of an investment, 12% in the second year and 10% in the third year. 9.36% 9.27% 9.30% 9.33%
Explanation:
3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?ootbicyblnhjbjgfvkgjvjggf Winston hero Bennington's m but cruel Bob ERM TTC well weep 0 to do is SK UV FLP if to to to is to to us so is do is to is
True or false, In a neutral atom of an element, the number of protons always equals the number of electrons.
Answer:
true
Explanation:
As an atom with no charge have same number of proton and electrons
A 15.8 g sample contains 3.60 g F, 4.90 g H, and 7.30 g C. What is the percent composition of hydrogen in this sample?
Answer: 22.7848% F or 23%
Explanation: %F = 3.6g/15.8g • 100% = 22.7848% F
The percentage composition of hydrogen in the given sample is equal to 31%.
What is percentage composition?The percentage composition of a given compound can be described as the ratio of the quantity of each element to the total quantity of individual elements in the compound multiplied by 100. The quantity can be measured in terms of grams of the elements present in the sample.
The percent composition is expressed in its composition in terms of all the elements present. Thus, it helps in the chemical analysis of any given compound.
The percentage composition is expressed using the following formula,
Percentage composition of E = (E/T) × 100
Where E represents the total quantity of element E present in the compound and T represents the total quantity of all the elements present in the compound.
Given, the mass of the F, H, and C is 3.60g, 4,90 g, and 7.30 g respectively.
The total mass of the given sample = 15.8 g
The mass of the hydrogen in the sample = 4.90 g
The percent composition of H = (4.90/15.8) × 100 = 31 %
Therefore, the percent composition of hydrogen in this sample is 31%.
Learn more about percent composition, here:
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Write the balanced chemical equation when carbonate ores are heated in a limited supply of air.
Answer:
MCO₃ (s) -> MO (s) + CO₂ (g)
Explanation:
M = a metal
This process is called calcination and is generally used to remove impurities. It's most common use is to remove carbon from limestone.
CaCO₃ (s) -> CaO (s) + CO₂ (g)
Help me please please
where is the directions here?
I cannot answer this if no directions
How are conduction, convection, and radiation different? Conduction transfers thermal energy by . Convection transfers thermal energy by . Radiation transfers thermal energy by .
Answer:
See explanation
Explanation:
There are three modes of heat transfer; conduction, convection and radiation.
Conduction refers to the transfer of heat without the actual movement of the particles of matter.
Convection is the transfer of heat by the actual movement of the particles of matter.
Radiation is the transfer of heat without a material medium.
Hence the three modes of heat transfer differ in the actual mechanism by which heat energy is transferred as shown above.
Answer:
The movement of molicules
The movement of a fluid
Electromagnetic Waves
Explanation:
Trust me
Which statement is the best description of a chemical bond
Answer:
What are your given options? I can't answer unless I know those :)
Explanation:
Heat is most closely related to which kind of energy?
O nuclear
electrical
thermal
chemical
Answer:
C thermal
Explanation:
Cotton plant is mainly harvested at flowering stage true false
Compare the energy requirements of a 50 year old woman and 50 year old man.
Explanation:
For both men and women, the basics of a balanced diet are the same. Men have higher caloric requirements than women since they have a bigger body (both in height and weight) and more muscular mass.
So, Men needs more energy.
50 year old woman require less energy than 50 year old man.
The partial pressure of carbon dioxide in air varies with the seasons. Would you expect the partial pressure in the Northern Hemisphere to be higher in the summer or winter
Answer:
It will be higher in the summer.
Explanation:
Usually, the winter season is more harsh a weather on leaves than summer because it is wet season and thus has less sunlight and this means there will be less photosynthesis reactions and therefore it means the partial pressure will be lesser here unlike in the summer when it is a more warm and dry weather with sunlight where photosynthesis reactions will be more favorable to occur.
Thus, CO2 which is a great component of photosynthesis is used more in the summer and as such the partial pressure in the summer will be higher.
describe the formation of ionic bonds in potassium chloride compound (5 marks)
Answer:
When the two atoms are in contact, potassium readily transfers its outer electron to chlorine which readily accepts it, resulting in both atoms achieving a state of eight outermost electrons. With this electron transfer, the ionic bond in KCl is formed.
Locations Cost of land Cost of equipment Cost of mining and reclamation Time taken to mine the area 1 $100,000 $10,000 $5,000 per day 30 days 2 $35,000 $6,000 $4,500 per day 45 days 3 $30,000 $7,500 $3,500 per day 120 days 4 $40,500 $8,000 $7,000 per day 65 days Considering all costs, which location will cost the least to the company to mine?
Answer:
Location 2 will cost the least to the company to mine.
Explanation:
a) Data and Calculations:
Locations Cost of land Cost of Cost of mining Time taken to
equipment and reclamation mine the area
1 $100,000 $10,000 $5,000 per day 30 days
2 $35,000 $6,000 $4,500 per day 45 days
3 $30,000 $7,500 $3,500 per day 120 days
4 $40,500 $8,000 $7,000 per day 65 days
Locations Cost of land Cost of Cost of mining Total
equipment and reclamation Costs
1 $100,000 $10,000 $150,000 ($5,000 * 30) $260,000
2 $35,000 $6,000 $202,500 ($4,500 * 45) $243,500
3 $30,000 $7,500 $420,000 ($3,500 * 120) $457,500
4 $40,500 $8,000 $445,000 ($7,000 * 65) $503,500
what is the formula of silver sulphate
Answer:
Ag2SO4
Explanation:
Calculate the average atomic mass for element X
Answer:
39.02
Explanation:
From the question given above, the following data were obtained:
Isotope A:
Mass of A = 38
Abundance of A (A%) = 9.67%
Isotope B:
Mass of B = 39
Abundance of B (B%) = 78.68%
Isotope C:
Mass of C = 40
Abundance of C (C%) = 11.34%
Isotope D:
Mass of D = 41
Abundance of D (D%) = 0.31%
Average atomic mass of X =?
The average atomic mass of X can be obtained as follow:
Average = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100] + [(Mass of D × D%)/100]
= [(38 × 9.67)/100] + [(39 × 78.68)/100] + [(40 × 11.34)/100] + [(41 × 0.31)/100]
= 3.6746 + 30.6852 + 4.536 + 0.1271
= 30.02
Thus, the average atomic mass of X is 39.02
Glycerin, , is a nonvolatile liquid. What is the vapor pressure of a solution made by adding glycerin to at
Complete question is;
Glycerin, C3H8O3, is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 164 g glycerin to 338 mL H2O at 39.8°C?
The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.0992 g/cm³
Answer:
28 torr
Explanation:
Let's first find the number of moles of water in 338 mL.
Molar mass of water = 18 g/mole
Formula for number of moles = mass/molar mass.
Mass = density × volume = 0.0992 × 338 = 33.5296 g
Thus;
Number of moles = 33.5296/18 = 1.863 moles.
Let's use the same procedure to find the Number of moles of glycerine.
Molar mass of glycerine from online values = 92.1 g/mol
Thus;
n_glycerine = (mass)/92.1
We have mass and density as 164 g and 0.0992 g/cm³ respectively.
n_glycerine = 164/92.1
n_glycerine = 1.78
Total moles of solution = 1.863 + 1.78 = 3.643 moles
We are told that The vapor pressure of pure water at 39.8°C is 54.74 torr
Thus, since water dominates, then vapour pressure of solution = (1.863/3.643) × 54.74 ≈ 28 torr
Put these atoms in order from most negative overall charge to least negative
overall charge.
11 Atom X: 104 protons, 102 electrons
11 Atom B: 24 protons, 18 electrons
1 Atom Q: 15 protons, 16 electrons
11. Atom P: 7 protons, 10 electrons
Answer:
3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?
Explanation:
Put these atoms in order from most negative overall charge to least negative
overall charge.
11 Atom X: 104 protons, 102 electrons
11 Atom B: 24 protons, 18 electrons
1 Atom Q: 15 protons, 16 electrons
11. Atom P: 7 protons, 10 electrons
The most common carrier of communicable diseases are
a.cockroach
b.housefly
c.mosquito
d.spider
housefly
Explanation:
Because it one of the affective vector of disease carrier and it always roam towards wastes and dirty materials likely to get attracted . And it carries contagious disease from hospitals , infected patients , etc .
i need to know soon. HELP
PLEASE
Answer:
D..
carbonate and sulphate
Solubility of which salts does not dependent on temperature.Any three.
Answer:
any salt
sodium chloride
callcium chloride
potassium chloride
Explanation:
There is no general effect of temperature on the solubility of salts.effect of increase temperature on the solubilty of NaCl is not significant because it is more soluble even at low temperature. The salt like potassium iodide (KI) has negative heat of solution so it's solubility decreases with increase of temperature…
write your 5 ways how to you can help earth
Answer:
any 5 ways to prevent earth are:
1.using ( 3R) principles Reduce, reuse, and recycle.
2.Educate yourself
3.Conserve water resources and other natural resources
4.Use long-lasting light bulbs.
5.stop deforestation and start afforestaion
8. A saturated solution of Ag Croq has a silver-ion concentration of 1.3 x 10-4M. Which is the Ksp of Ag CrO 4?
O 1.3 x 10-4
O 3.9 x 10-12
O 6.5 x 10-5
O 1.1 x 10-12
Answer: The [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].
Explanation:
Given: [tex][Ag^{+}] = 1.3 \times 10^{-4} M[/tex]
The reaction equation will be written as follows.
[tex]Ag_{2}CrO_{4} \rightleftharpoons 2Ag^{+} + CrO^{2-}_{4}[/tex]
This shows that the concentration of [tex]CrO^{2-}_{4}[/tex] is half the concentration of [tex]Ag^{+}[/tex] ion. So,
[tex][CrO^{2-}_{4}] = \frac{1.3 \times 10^{-4}}{2}\\= 0.65 \times 10^{-4} M[/tex]
The expression for [tex]K_{sp}[/tex] of this reaction is as follows.
[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}][/tex]
Substitute values into the above expression as follows.
[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}]\\= (1.3 \times 10^{-4})^{2} \times 0.65 \times 10^{-4}\\= 1.1 \times 10^{-12}[/tex]
Thus, we can conclude that the [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].
Explain the sharing of electrons between a water molecule that forms four hydrogen bonds with the other four water molecules
Answer:
The sharing of electrons between a water molecule that forms four hydrogen bonds with the other four water molecules:
Explanation:
The hydrogen bond is a weak electrostatic force of attraction that exists between a covalently bonded H-atom and a highly electronegative atom like N,O or F.
In the case of the water molecule,
the highly electronegative atom is Oxygen and the intermolecular hydrogen bond in water is as shown below:
Thus H-bond is a weak electrostatic attraction formed between H-atom and O-atom in water.