Answer:
Most pure metals, like aluminium, silver and copper, come from the Earth's crust. They are found in ores – solid materials called minerals, usually occurring in rock, from which the pure metal has to be extracted. The properties of pure metals can be improved by mixing them with other metals to make alloys.a metal is an element that readily forms positive ions (cations) and has metallic bonds
coke is a strong stimulant made from coca leaves
help help help help help
Answer:
Temporary hardness is a type of water hardness caused by the presence of dissolved bicarbonate minerals (calcium bicarbonate and magnesium bicarbonate). ... However, unlike the permanent hardness caused by sulfate and chloride compounds, this "temporary" hardness can be reduced by boiling the water.
1. How many liters of a 0.50 M solution are needed to give 3.5 moles of solute?
Answer:
The volume of solution in liters required to make a 0.250 M solution from 3.52 moles of solute is 14.08 liters of solution
Explanation:
The question relates to the definition of the concentration of a solution which is the number of moles per liter (1 liter = 1 dm³) of solution
Therefore we have;
The concentration of the intended solution = 0.250 M
Therefore, the number of moles per liter of the required resolution = 0.250 moles
Therefore, the concentration of the required solution = 0.250 moles/liter
The volume in liters of the required solution that will have 3.52 moles of the solute is given as follows;
The required volume of solution = The number of moles of the solute/(The concentration of the solution)
∴ The required volume of solution = 3.52 moles/(0.250 moles/liter) = 14.08 liters
The required volume of solution to make a 0.250 M solution from 3.52 moles of solute = 14.08 liters.
Therefore the number of liters required to make a 0.250 M solution from 3.52 moles of solute = 14.08 liters.
Using the diagram, which two planes would intersect in HG?
Answer please .. :)
Answer:
I think D
Explanation:
it has both H and G in the planes.
Please help will mark Brainliest!!!
How many grams of HCL (hydrochloric acid) can you make with 50 grams of Cl.
H + Cl -> HCL is the balanced equation
Answer:
Explanation:
It's 21 /
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Which product forms from the synthesis reaction between sodium (Na) and
sulfur (S)?
O A. Nasz
B. Nas
C. Na2S
O D. Na2S2
Answer:
Answer is C
Explanation:
the valency of sulphur is 2 ans sodium is 1
by crossing it forms NA2S
For each of the following questions give the name of an element from period 2 lithium to neon which matches the description elements may be used once more than once or not at all
a) an element which has atoms with a full outer shell of electrons
b) an element which exists as both diamond and graphite
c) an element that reacts vigorously with cold water
d) a soft metallic element which is stored in oil
PLEASEEE
The elements of period 2 that satisfy the descriptions are;
a) Neon
b) carbon
c) sodium
c) sodium
What is the periodic table?We know that the periodic table is an arrangement of the elements in the order of their reactivity. We know that the elements that we have are arranged into groups and periods.
The elements that are in the same group do have similar chemical properties while the elements that are in the same period do have the same number of shells. The properties of the elements in a periods tends to change across the period.
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1. Using the structural formulas for ammonia (NH3 on the left) and hexane (C6H14 on the right) below which statement explains what will happen when ammonia and hexane are mixed?
A. Hexane will dissolve with ammonia if you stir them together for 10 minutes
B. Ammonia and hexane will not dissolve because one molecule is polar and the other is non polar.
C. Ammonia and hexane will dissolve together
D. Ammonia and hexane will not dissolve because one molecule is ionic and the other is non polar
2. If you add water to 750.0 mL of a 2.800 M KCl solution, and its molarity changes to 1.500 M, what will the new volume be?
1200 mL
401.0 mL
1400 mL
800.0 mL
Answer:
1. B. Ammonia and hexane will not dissolve because one molecule is polar and the other is non polar.
2. 1400 mL
Explanation:
In chemistry, like dissolve like! Ammonia is a polar molecule having a significant dipole moment owing to its three N-H bonds. On the other hand, hexane is a purely non-polar hydrocarbon hence the two substances can never dissolve in each other.
From the dilution formula;
C1V1=C2V2
C1= Initial concentration of the solution
V1 = Initial volume of the solution
C2 = Final concentration of the solution
V2= Final volume of the solution
2.8 M * 750.0 mL = 1.5 M * V2
V2 = 2.8 M * 750.0 mL/1.5 M
V2 = 1400 mL
Excessive use of chemical fertilizer cause chemical pollution.How?
Explanation:
Chemical fertilizers raise crop yields, but their heavy usage has hardened the soil, diminished fertility, reinforced pesticides, contaminated air and water, and emitted greenhouse gases, posing health and environmental risks.
Dipole-dipole interactions are (weaker than, stronger than, equal to) hydrogen bonds.
Answer and Explanation:
Dipole-Dipole interactions are weaker than hydrogen bonds.
Hydrogen bonds are a form of dipole-dipole interactions, being the strongest form of dipole-dipole interactions.
#teamtrees #PAW (Plant And Water)
What is the electron configuration of the calcium ion?
Answer: Calcium ion Ca² : 1 s² 2s² 2p ^6 (sorry I don't get 6 similar way as 2) 3s² 3p^6
Also 18 electrons, because Calcium donates two 4s electrons
Explanation:
In a reaction 25.00mL of nitric acid required 51.4mL of 0.73M calcium hydroxide. Calculate the grams of nitric acid per liter of solution
Answer:
47.27 g HNO₃
Explanation:
The reaction between nitric acid (HNO₃) and calcium hydroxide (Ca(OH)₂) is the following:
2HNO₃(aq) + Ca(OH)₂(aq) → Ca(NO₃)₂ + 2H₂O(l)
According to the chemical equation, 2 moles of HNO₃ reacts with 1 mol of Ca(OH)₂. At the point of total neutralization, the total number of moles of HNO₃ reacts with the total number of moles of Ca(OH)₂:
2 x moles HNO₃ = moles Ca(OH)₂
The number of moles is equal to the product of molarity of the solution (M) and the volume in liters (V):
M(HNO₃) = ?
M(Ca(OH)₂) = 0.73 M
V(HNO₃) = 25.00 mL x 1 L/1000 mL = 0.025 L
V(Ca(OH)₂) = 51.4 mL x 1 L/1000 mL = 0.0514 L
So, we can write the equation at neutralization point as:
2 x (M(HNO₃) x V(HNO₃)) = M(Ca(OH)₂) x V(Ca(OH)₂)
From this, we can calculate the molarity of HNO₃:
M(HNO₃) = (M(Ca(OH)₂) x V(Ca(OH)₂))/2 x V(HNO₃)
= (0.73 M x 0.0514 L)/(2 x 0.025 L)
= 0.75 M HNO₃
We can convert the molarity from M (mol/L) to g/L by using the molecular weight of HNO₃:
Mw(HNO₃) = 1 g/mol H + 14 g/mol N + (3 x 16 g/mol O) = 63 g/mol
Finally, we multiply the molarity by the molecular weight to obtain the grams of nitric acid per liter of solution:
0.75 mol/L HNO₃ x 63 g/mol = 47.27 g HNO₃
khan academy sucks. can someone answer this? :)
how many grams of sulphur contain 3.0×1021 atoms
Answer:
There are 0.16 g of sulphur in 3.0 × 10²¹ atoms.
Explanation:
One mole of a substance contains 6.02 × 10²³ particles
One mole of sulphur atom contains 6.02 × 10²³ atoms
Number of moles of sulphur present in 3.0 × 10²¹ atoms = 3.0 ×10²¹/6.02 10²³
Number of moles of sulphur atom = 0.00498 moles of sulphur atom
The mole of a substance is related to its mass by a quantity known as molar mass which is defined as the mass of one mole of that substance.
Molar mass of sulphur atom = 32 grams per mole (g/mol)
Mass of 0.00498 moles of sulphur atom = 0.00498 moles × 32 g/mol
Mass of sulphur = 0.16 g
Therefore, there are 0.16 g of sulphur in 3.0 × 10²¹ atoms.
Alia needs to order the following isotopes by atomic number. Use what you know about atomic number and
isotopes to drag and drop the tiles in order of increasing atomic number from lowest to highest.
Silver-109
Cadmium-106
Rhodium-122
Indium-110
Palladium-109
Answer:
Rhodium-122 < Palladium-109 < Silver-109 < Cadmium-106 < Indium-110
Explanation:
Atomic number - Number of protons.
The number displayed at the end of the element in this question represents the mass number (Number of protons + Number of neutrons).
The atomic number of the isotopes are given below;
Silver-109 --> 47
Cadmium-106 --> 48
Rhodium-122 --> 45
Indium-110 --> 49
Palladium-109 --> 46
Arranging in order of increasing atomic number from lowest to highest;
Rhodium-122 < Palladium-109 < Silver-109 < Cadmium-106 < Indium-110
2NO (g) + O2 (g) →2NO2 (g) At equilibrium [NO] = 2.4 × 10 -3 M, [O2] = 1.4 × 10 -4 M, and [NO2] = 0.95 M.
Answer:
[tex]K=1.12x10^9[/tex]
Explanation:
Hello there!
Unfortunately, the question is not given in the question; however, it is possible for us to compute the equilibrium constant as the problem is providing the concentrations at equilibrium. Thus, we first set up the equilibrium expression as products/reactants:
[tex]K=\frac{[NO_2]^2}{[NO]^2[O_2]}[/tex]
Then, we plug in the concentrations at equilibrium to obtain the equilibrium constant as follows:
[tex]K=\frac{(0.95)^2}{(0.0024)^2(0.00014)}\\\\K=1.12x10^9[/tex]
In addition, we can infer this is a reaction that predominantly tends to the product (NO2) as K>>>>1.
Best regards!
Which is which, acid or base?
Answer:
HCI - BASE
KOH - ACID
H2SO4 - ACID
H30 + :- BASE
NAOH - ACID
1.
John ground some coffee beans into little pieces. He put them into a coffee filter and poured
800 cm3 of boiling water over them to make a jug of coffee.
coffee filter
Coffee
Beans
ON
jug of coffee
(a) Complete the sentences below. For each sentence, choose one of the following
words.
insoluble
soluble
solution
solvent
(0)
The liquid in the jug is brown because parts of the coffee beans
are
in water.
1 mark
What are the three possible combinations of the two types of
proteins that can be found on a person's red blood cells?
Answer:
WHITE BLOOD SELL?
Explanation:
Balance the following equation: N2 + H2 --> NH3
Write the coefficients that you decide balance the equation like this 3, 4, 3. If you do not add a coefficient in front of an element or compound, use a 1 in your answer. For instance the for this balanced equation: 2H2 + O2 --> 2H2O you would write your answer: 2, 1, 2
Answer:
3, 2
Explanation:
Balanced equation:
N2 + 3 H2 = 2 NH3
The different between molecules in a liquid and molecules in a gas
Answer:
Gases, liquids and solids are all made up of atoms, molecules, and/or ions, but the behaviors of these particles differ in the three phases. ... gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.
For which of the reactions listed below will Gibbs free energy always be.
positive?
O A. An exothermic reaction that decreases in entropy
B. An exothermic reaction that increases in entropy
O C. An endothermic reaction that decreases in entropy
D. An endothermic reaction that increases in entropy
I think the answer is: C. An endothermic reaction that decreases in entropy
An endothermic reaction that decreases in entropy. Hence, option C is correct.
What is entropy?Entropy is the energy of a system that is unuseful to do work.
For a reaction to be spontaneous, the Gibbs' Free Energy must be negative.
The equation for Gibbs Free energy is given by:
G= H-TS
Where, G = Gibbs free energy
H = Enthalpy of the reaction
T = Temperature of the system
S = Entropy of the system
Sign convention for all the quantities:
For H: It is negative for exothermic reactions and positive for endothermic reactions
For S: It is positive when there is an increase in entropy and it is negative when there is a decrease in entropy.
If we want G to be negative, the conditions necessary are:
G= (-ve) - (+ve) = -ve
The product of temperature and entropy must be positive and that will be positive when there is increase in entropy at any temperature.
Hence, option C is correct.
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Help me please I’ll give brainliest answer
Answer:
the answer is c I believe
I need help please i need to turn this in today
Answer:
Natural phenomena such as melting glaciers is due to the rise in temperature. This will result to extinction of flora and fauna. Moreover it can cause extreme flooding due to rise in water level in other water bodies such as rivers, lakes
Which of the following describes how covalent
compounds differ from ionic compounds?
A. ionic bonds form between non metals only. B. ionic bonds are more likely to be gas. C. covalent bonds have a lower melting and boiling point. D. covalent bonds are more likely to be solids
Answer: The answer is C
covalent bonds have a lower melting and boiling point
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How are cations formed? A. when one or more electrons of an atom disintegrate B. when an atom gains one or more electrons from other atoms C. when an atom shares one or more electrons with another atom D. when an atom loses one or more electrons
Answer:
D
Explanation:
When an atom loses an electron the number of electrons exceeds the number of protons. This means that the negative charge induced by the electrons exceeds the positive charge induced by the protons.
El ozono es una sustancia pura cuya molécula está formada por tres átomos de oxígeno, O3. Se encuentra en pequeñas cantidades en la estratosfera formando una ligera capa alrededor de la tierra. El ozono es un filtro para ciertas radiaciones como los rayos ultravioleta que provienen del sol y son muy perjudiciales. Desde hace varias décadas se ha observado una disminución de O3 en el polo sur y comienza a disminuir en el polo norte formando un agujero en esta capa. Qué consecuencias trae para los seres vivos la destrucción de la capa de ozono y cómo podría revertirse este deterioro en dicha capa?
Answer and Explanation:
Dado que la capa de ozono protege la vida en la Tierra actuando como filtro de radiaciones nocivas del Sol, su destrucción trae como consecuencia un aumento de la radiacion UV que puede provocar:
- daños en animales y en el hombre: aumento de casos de cáncer de piel, cataratas en ojos, debilitamiento del sistema inmune.
- alteración en el desarrollo de especies vegetales .
- contribución al efecto invernadero y al calentamiento global.
Para revertir el deterioro de la capa de ozono, podemos tomar algunas medidas:
- no utilizar productos que contengan clorofluorocarbonos (CFC), como por ejemplo algunos aerosoles.
- evitar el uso de productos que contengan halones
- evitar el uso de hidrofluorcarbonos (HFCF)
Estos compuestos químicos reaccionan y destruyen el ozono, por lo que si evitamos utilizarlos, con el tiempo la capa de ozono se recuperará.
The diagram shows the molecular structure of butane. What is the chemical
formula for butane?
Butane
H
Н
Hн
н—с-с-с-с-Н
|| []
Н н н Н
А. 4C1ОН
В. С4Н10
С. 4CH10
D. HC4H
Answer: B
Explanation: sorry if I'm too late but i just did this question and that was the right answer
There are 5 moles of N20 at STP. What is the density?
Answer:
5 mole of N2O : 112 litre of N2O
5 mole of N2O : 220 g of N2O
Then,
Density = mass/ volume
= 220/112
= 1.96 g per litre
Calculate the amount of copper obtained by this reaction
do i have to know the chemical and physical properties of alloys? only chemistry students answer this.
Answer:
yes you do so you know how strong it is how maluble it's is so it can be customised to it's specific use
Answer:
alloy's properties are usually different from those of its component elements. Alloy constituents are usually measured by mass. Unlike pure metals, most alloys do not have a single melting point; rather, they have a melting range in which the substance is a mixture of solid and liquid.
physical properties of alloys:-Alloy steels have a wide range of special properties, such as hardness, toughness, corrosion resistance, magnetizability, and ductility. Nonferrous alloys, mainly copper–nickel, bronze, and aluminum alloys, are much used in coinage.
chemical properties of alloys:-Pure metals are useful but their applications are often limited to each individual metal's properties. Alloys allow metal mixtures that have increased resistance to oxidation, increased strength, conductivity, and melting point; Essentially any property can be manipulated by adjusting alloy concentrations.
dnt learn all thr properties.
these are the main properties..u can learn thse only. hope it will help u