Answer: The ion that contribute to water hardness are:
--> a. Ca2+
--> b. (HCO)3^- and
--> c. Mg2+
While K+ DOES NOT contribute to water hardness.
Explanation:
WATER in chemistry is known as a universal solvent. This is so because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. It is composed of elements such as hydrogen and oxygen in the combined ratio of 2:1.
Water is said to be HARD if it does not lather readily with soap. There are two types of water hardness:
--> Permanent hardness: This is mainly due to the presence of CALCIUM and MAGNESIUM ions in the form of soluble tetraoxosulphate(VI) and chlorides. These ions are removed by adding washing soda or caustic soda.
--> Temporary hardness: This is due to the presence of calcium HYDROGENTRIOXOCARBONATES. It can be removed by boiling and using slaked lime.
Therefore from the above given ions, Ca2+,(HCO)3^- and Mg2+ contributes to water hardness.
The acid dissociation constant, Ka, of HNO3 is 4.0 x104. What does the ka
value indicate about this compound?
A. HNO3 is neither an acid nor a base,
B. HNO3 is a strong acid.
C. HNO3 is a weak acid
D. HNO3 is a strong base.
Answer:
i thing its b
Explanation:
The acid dissociation constant (Ka) is a measure of the strength of an acid in solution. In HNO₃ (nitric acid), the given Ka value is 4.0 x 10⁴. It represents the equilibrium constant for the dissociation reaction of an acid in water. Therefore, option B is correct.
The dissociation constant often denoted as Kd, is a measure of the strength of the interaction between a ligand and a receptor or between a substrate and an enzyme.
A high Ka value indicates a strong acid, while a low Ka value indicates a weak acid. In this case, the Ka value of 4.0 x 10⁴ for HNO₃ is relatively high.
To learn more about the dissociation constant, follow the link:
https://brainly.com/question/28197409
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If the Air Pressure on a mountain Is 0.3 atm what is this value mmHg? 1atm = 760mmHg = 101kPa
Answer:
IS IT MULTIPLE CHOICE
Explanation:
PLZZZ HELPPPPPPPPPPPPPPPPPPPPP
Answer:
1 +-0.05cm
Explanation:
because this is more suitable
if B is completely insoluble in water. Your description should include the volume of solvent required.6b) Assuming that 2 mg of the impurity B are present along with 100 mg of A, describe how you can purify A if B has the same solubility behavior as A. Will one crystallization produce pure A
Answer:
1st step : mix the mixture with water that way A will dissolve while B will remain insoluble.
2nd step :To get B from the solution, filter the mixture and get B
3rd step : To get A from the solution evaporate the new solution
Explanation:
Assuming 2mg of impurity B to be present
100 mg of A is present as well
Method of purifying A given that B is of same solubility
Dissolve the 100 mg of A with 30 mL
1st step : mix the mixture with water that way A will dissolve while B will remain insoluble.
2nd step :To get B from the solution, filter the mixture and get B
3rd step : To get A from the solution evaporate the new solution
. ¿Cuantos moles de Fosfato de Bario se producen cuando reaccionan 0.38 mol de Nitrato
de bario? Suponga que el ácido fosfórico está en exceso. Base sus cálculos en la siguiente
ecuación.
Ba(NO3)2(aq) + HAPO.(aq)
Ba,(PO.),(s) + HNO3(aq)
-
Respuesta:
0.13 mol
Explicación:
Paso 1: Escribir la ecuación química balanceada
3 Ba(NO₃)₂ + 2 H₃PO₄ ⇒ Ba₃(PO₄)₂ + 3 H₂O
Paso 2: Establecer la relación molar apropiada
La relación molar de Ba(NO₃)₂ a Ba₃(PO₄)₂ es 3:1.
Paso 3: Calcular cuantos moles de fosfato de bario se producen a partir de 0.38 moles de nitrato de bario
0.38 mol Ba(NO₃)₂ × 1 mol Ba₃(PO₄)₂/3 mol Ba(NO₃)₂ = 0.13 mol Ba₃(PO₄)₂
What would happen to the Earth's hydrosphere if there were no atmosphere?
1. As you go across a period, what is a useful comparison point?
A.
oxides
B.
halides
C.
hydrides
D.
hydroxides
-----
2. Most elements are
A.
allotropes
B.
nonmetals
C.
metalloids
D.
metals
----
3. A metalloid is a(n) __ conductor of heat and electricity than a metal.
A.
better
B.
worse
C.
equal
D.
cannot be determined
-----
4. What causes the formation of allotropes?
A.
pressure
B.
light
C.
temperature
D.
all of the above
----
As you move __and __ elements become more metallic.
A.
left, down
B.
right, down
C.
right, up
D.
left, up
------
5. All of the following metalloids form allotropes except
A.
B
B.
Si
C.
Te
D.
Po
------
6. What is a chemical property of a metal?
A.
malleable
B.
ductile
C.
positive oxidation states
D.
conducts heat and electricity
----
Explanation:
1. As you go across a period, what is a useful comparison point?
A.
oxides
2. Most elements are
A.
allotropes
3. A metalloid is a(n) __ conductor of heat and electricity than a metal.
A.
better
4. What causes the formation of allotropes?
A.
pressure
As you move __and __ elements become more metallic.
A.
left, down
5. All of the following metalloids form allotropes except
A.
B
6. What is a chemical property of a metal?
A.
malleable
Soybeans is used in food production and cooking in 2007 United States produced 3.06 billions bushels of soybeans and 65% of the harvest was used to make soybeans oil
Answer:
1.071
Explanation:
Answer:
Find the percentage of soybeans used for other purposes:
100% − 65% = 35%.
Multiply the result (35%) by the total bushels of soybeans produced:
35
100
=
0.35
.
0.35 × 3.06 billion bushels = 1.071 billion bushels
The amount of soybeans used for other purposes was 1.071 billion bushels.
Explanation:
PLATO
La is element 57 on the periodic table a sample contains 2.82 * 10€25 power atoms of La calculate the amount of LA
Answer:
[tex]n=46.8molLa\\\\m=6.50x10^3gLa[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate both moles and grams of lanthanum by using the Avogadro's number as a relationship of atoms to moles and its atomic mass as a relationship to moles to grams to obtain the following:
[tex]n=2.82x10^{25}atomsLa*\frac{1molLa}{6.022x10^{23}atomsLa}=46.8molLa\\\\m=46.8molLa*\frac{138.9gLa}{1molLa} =6.50x10^3gLa[/tex]
Regards!
I need help with this
Name:
Date:
Lab 2:
Density and Specific Heat
Pre-lab questions:
1. Density of aluminum is 2.702 g/cm². Calculate the mass of a rectangular aluminum solid with a length
of 7.45 cm, a width of 4.78 cm, and a height of 5.25 cm.
2. When measuring mass and volume of a liquid or gas to determine density, temperature must be
measured. Why does it depend on the temperature?
Answer:
1. 505g is the mass of the aluminium.
2. The answer is in the explanation
Explanation:
1. To solve this question we need to find the volume of the rectangle. With the volume and density we can find the mass of the solid:
Volume = 7.45cm*4.78cm*5.25cm
Volume = 187cm³
Mass:
187cm³ * (2.702g/cm³) = 505g is the mass of the aluminium
2. When the temperature of a liquid increases, the volume increases doing the density decreases because density is inversely proportional to volume. And works in the same way for gases because the temperature produce more collisions and the increasing in volume.
atomic number of element is 15 write a formula of an oxide
Answer:
Atomic Number. 15=phosphorus
Valency=3
So, Oxide=P203
Calculate the amount of heat needed to melt 89.9 g of solid methanol (CH3OH) and bring it to a temperature of 49.1C.
Answer:
20075.35 J
Explanation:
We'll begin by calculating the number of mole in 89.9 g of CH₃OH. This can be obtained as follow:
Mass of CH₃OH = 89.9 g
Molar mass of CH₃OH = 12 + (3×1) + 16 + 1
= 12 + 3 + 16 + 1
= 32 g/mol
Mole of CH₃OH =?
Mole = mass / molar mass
Mole of CH₃OH = 89.9 / 32
Mole of CH₃OH = 2.81 moles
Next, we shall determine the heat required to melt the solid methanol (CH₃OH). This can be obtained as follow:
Mole of CH₃OH (n) = 2.81 moles
Heat of fusion (Hբ) = 3.17 KJ/mol
Heat required to melt CH₃OH (Q₁) = ?
Q₁ = n × Hբ
Q₁ = 2.81 × 3.17
Q₁ = 8.9077 KJ
Converting to J
Q₁ = 8.9077 × 1000
Q₁ = 8907.7 J
Next, we shall determine the heat required to change the temperature of methanol to 49.1 °C. This can be obtained as follow:
Mass of CH₃OH (M) = 89.9 g
Initial temperature (T₁) = 0 °C
Final temperature (T₂) = 49.1 °C.
Specific heat capacity of CH₃OH (C) = 2.53 J/gºC
Heat required to change the temperature (Q₂) =?
Q₂ = MC(T₂ – T₁)
Q₂ = 89.9 × 2.53 × (49.1 – 0)
Q₂ = 89.9 × 2.53 × 49.1
Q₂ = 11167.65 J
Finally, we shall determine the total heat. This can be obtained as follow:
Heat required to melt CH₃OH (Q₁) = 8907.7 J
Heat required to change the temperature (Q₂) = 11167.65 J
Total heat required (Q) =?
Q = Q₁ + Q₂
Q = 8907.7 + 11167.65
Q = 20075.35 J
Therefore, the total heat required to melt the methanol and bring it to a temperature of 49.1 °C is 20075.35 J
The main product of free radical bromination of methane is
A) ethane
B) chloromethane
C) bromonethane
D) bromine
Answer: C
Explanation:
Group the elements into pairs that would most likely exhibit similar chemical properties. It does not matter which pair of elements is pair 1, pair 2, or pair 3, so long as the correct elements are paired.Pair 1 Pair 2 Pair 3 Answer Bank Mg St Kr Ne+
As P
Answer: Pair 1 has Mg and Sr, Pair 2 has Kr and Ne, Pair 3 has As and P.
Explanation:
A periodic table is a group of elements presented in a tabular form where elements are arranged in a series of 7 rows and 18 columns.
The vertical columns are known as groups and horizontal rows are known as periods.
The elements having similar chemical properties are arranged in one group.
Magnesium (Mg) is the 12th element of periodic table placed at Group 2 and Period 3
Strontium (Sr) is the 38th element of periodic table placed at Group 2 and Period 5
Krypton (Kr) is the 36th element of periodic table placed at Group 18 and Period 4
Neon (Ne) is the 10th element of periodic table placed at Group 18 and Period 2
Arsenic (As) is the 33rd element of periodic table placed at Group 15 and Period 4
Phosphorus (P) is the 15th element of periodic table placed at Group 15 and Period 3
As magnesium and strontium are present in the same group, they will have similar chemical properties. Similarly, krypton and neon will form the second pair. Likewise, arsenic and phosphorus will form a pair.
Hence, Pair 1 has Mg and Sr, Pair 2 has Kr and Ne, Pair 3 has As and P.
How many moles are present in a sample if it consists of 5.61x1022 particles? Report your answer to 3 decimal places. Do not include units.
Answer:
The mole is defined as a collection of 6.022 × 1023 particles.
The atomic mass given on a periodic table that is given in grams is the mass of
one mole (6.022 × 1023 particles) of that element
Explanation:
En una práctica experimental, para la obtención de cloruro cobaltoso, se hacen reaccionar 120 g de sulfuro cobaltoso de 60% de pureza con 30 cm3 de ácido nítrico concentrado (densidad 1,142 g/cm3, 69,8% en peso de HNO3), en presencia de ácido clorhídrico concentrado (densidad 1,19 g/cm3, 37,33 % en peso de HCl). Calcular:
a) El volumen de ácido clorhídrico concentrado que se requiere para la reacción.
b) La cantidad máxima de cloruro de cobalto (II) que se puede preparar.
c) El número de moléculas de monóxido de nitrógeno que se deprenden.
d) El número de átomos de azufre que se forman.
e) El número de moles de agua que se obtiene.
CoS + HNO3 + HCl → CoCl2 + NO + S + H2O
Answer: D
Explanation:
Utilicé traductor de español para responder esta pregunta
Explain how mile-a-minute vine could have a long-term effect on local ecosystems. Use evidence and scientific information about genetic traits, adaptation and factors in the environment to support your response.
A mile-A-minute vine would kill off a good number of native plants by out growing them , having bigger and stronger roots that absorb more nutrients and water. They also will grow faster and be able to get more sunlight
What is the initial pressure of a gas if it’s occupied a volume of 0.375 L but now occupies a volume of 1.25 L at a pressure of 95.5 K PA
Answer:
318 kPa
Explanation:
Step 1: Given data
Initial pressure (P₁): ?Initial volume (V₁): 0.375 LFinal pressure (P₂): 95.5 kPaFinal volume (V₂): 1.25 LStep 2: Calculate the initial pressure of the gas
Assuming constant temperature and ideal behavior, we can calculate the initial pressure of the gas using Boyle's law.
P₁ × V₁ = P₂ × V₂
P₁ = P₂ × V₂ / V₁
P₁ = 95.5 kPa × 1.25 L / 0.375 L = 318 kPa
I need information about
"forming colloid"
THANK YOU!
Answer:
Condensation methods from colloidal particles by aggregation of molecules or ions. Examples of colloids are really in common in evryday life, eg. Mayonnaise, butter, milk, gelatin, paper etc..
Every colloid consists of two parts :colloidal particles and the dispersing medium.
What is the scientific basis for the application of surimi production (gel formation)?
An article about half-lives describes a parent isotope. What is a parent isotope?
A. The isotope that forms from the radioactive decay of a less stable isotope.
B. The isotope that forms from the radioactive decay of a more stable isotope.
C. The isotope that undergoes radioactive decay to form a less stable isotope.
D. The isotope that undergoes radioactive decay to form a more stable isotope.
I think the answer is D.
Answer:
D. The isotope that undergoes radioactive decay to form a more stable isotope.
Explanation:
In radioactivity, isotopes of an unstable atom disintegrates/decays into more stable ones accompanied with the emissions of certain particles e.g alpha, gamma and beta particles.
In this process, the isotope of the atom that undergoes radioactive decay to form a more stable isotope is known as the PARENT ISOTOPE while the more stable isotope that arises from the decay is called the DAUGHTER ISOTOPE.
(238, 92) Uranium → (234,90) Thorium + (4,2) Helium
In the above reaction, Uranium is the parent isotope because it decays into a more stable isotope (Thorium).
Answer:
He's Right
Explanation:
i got it right
Select all the correct answers
When two generalizations can be made based on what you know about cycles of matter in a closed system?
New matter is added, and old matter is destroyed.
Matter changes its physical form, allowing it to return to its original state.
The amount of matter within the system remains the same
Matter and energy can cross the boundaries of the system.
The cycle has a well-defined starting and Stopping point
Answer:
A
Explanation:
In centigrade bromine has a melting point of -7 and a boiling point of 58. Room temperature is 20. What is bromine at this temperature? Answers- Solid Liquid Gas
Solid with some liquid. It has to be one of those/
Answer:
Bromine will be a liquid
What size volumetric flask would you use to create a 1.00M solution using 166.00 g of KI?
Answer:
A 1 liter volumetric flask should be used.
Explanation:
First we convert 166.00 g of KI into moles, using its molar mass:
Molar mass of KI = Molar mass of K + Molar mass of I = 166 g/mol
166.00 g ÷ 166 g/mol = 1 mol KIThen we calculate the required volume, using the definition of molarity:
Molarity = moles / litersLiters = moles / molarity
1 mol / 1.00 M = 1 LThe energy of a photon that has a frequency of 1.821 x 1016 5-1 is blank j?
Answer:
1.207 ××10⁻¹⁷ J
Explanation:
Step 1: Given and data
Frequency of the photon (ν): 1.821 × 10¹⁶ s⁻¹Planck's constant (h): 6.626 × 10⁻³⁴ J.sStep 2: Calculate the energy (E) of the photon
We will use the Planck-Einstein's relation.
E = h × ν
E = (6.626 × 10⁻³⁴ J.s) × ( 1.821 × 10¹⁶ s⁻¹) = 1.207 ××10⁻¹⁷ J
Which equation represents a combustion reaction?
2SO2 + O2 → 2SO3
Pb(NO3)2 + 2HCl → PbCl2 + 2HNO3
2C2H6 + 7O2 → 4CO2 + 6H2O
Ca + 2HCl → CaCl2 + H2
Answer:
2SO2 + O2 => 2SO3
Explanation:
Combustion reaction involves heating of a compound/element/substance in presences of oxygen.
Use the electronic configuration to explain the occurrence of period and groups to the periodic table.
Answer:
H2O
Explanation:
hydrogen has 1 electron
and oxygen has 6 electron which form a water molecule Atom
Pressurized metal gas cylinders are generally used to store commonly used gases in the laboratory. At times, it can be easier to chemically prepare occasionally used gases. For example, oxygen gas can be prepared by heating KMnO4(s) according to the following chemical reaction:
2KMnO4(s) → K2MnO4(s) + MnO2(s) + O2(g)
How many grams of KMnO4 would you need to produce 0.27 moles of O2, assuming 100% conversion?
Answer:
You need 85.32 grams of KMnO₄ to produce 0.27 moles of O2, assuming 100% conversion.
Explanation:
The balanced chemical reaction is:
2 KMnO₄ (s) → K₂MnO₄ (s) + MnO₂ (s) + O₂ (g)
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles participate in the reaction:
KMnO₄: 2 molesK₂MnO₄: 1 moleMnO₂: 1 moleO₂: 1 moleThen you can apply the following rule of three: if by stoichiometry 1 mole of O₂ is produced by 2 moles of KMnO₄, 0.27 moles of O₂ are produced by how many moles of KMnO₄?
[tex]moles of KMnO_{4} =\frac{0.27 moles of O_{2} *2moles of KMnO_{4} }{1mole of O_{2} }[/tex]
moles of KMnO₄= 0.54
The molar mass of KMnO₄ is 158 [tex]\frac{g}{mol}[/tex].
Then the amount of mass present in 0.54 moles of the compound can be calculated by:
0.54 moles* 158.034 [tex]\frac{g}{mol}[/tex]= 85.32 grams
You need 85.32 grams of KMnO₄ to produce 0.27 moles of O2, assuming 100% conversion.
How many joules of heat energy are required to raise the temperature of 100.0 g of aluminum by 120.0°C? The specific heat of aluminum is 0.897 J/g.°C. 2 3
Answer:
10764 J
Explanation:
Remember the equation for specific heat::
q = mcΔT
q = 100 x 0.897 x 120
q = 10764