plz help me I will mark as brainlest
All three metals react with cold water.
Complete the word equation for these reactions.
metal + water ➡️ _______ + ________
Answer:
metal oxide +hydrogen gas
Physical change does not produce a nee substance true or false
Answer:
ooooooooh .,.,.,.,.,.,
Answer:
True
TruePhysical change – A change in the size, shape, color, or state of matter of a substance. No new substance is produced.
9. Calculate the pOH and pH of a 0.35 M solution of the weak acid HCN.
Ka HCN = 4.8 x 10-10
Answer:
=0.35hcn20 4.7 x hcn(poh) =hcnty sa pointd
A student mixes some soap with water and then blows through a straw into the solution. Bubbles form. Do you think a chemical change has taken place? Explain
Answer:
No it has not.
Explanation:
The actual chemical compound has not changed, the materials have mixed but no reaction has taken place. Blowing the bubbles causes a physical change. Hope this helped!
Mixing soap and water and forming bubbles is a physical change as there is no change in composition.
What is a physical change?
Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.
Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.
They involve only rearrangement of atoms and are often characterized to be changes which are reversible.
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list atleast two examples of Arrhenius acids?
Answer:
HCl (hydrochloric acid) and H2SO4 (sulphuric acid)
I hope it helps.
PLS HELP ILL GIVE BRAINLIEST
Upload images that have physical and chemical properties
(six physical properties and 2 chemical properties)
Answer:
Explanation:
I hope this helps
In the following reaction, what is the quantity of heat (in kJ) released when 5.87 moles of CH₄ are burned?
CH₄ (g) + 2 O₂ (g) → CO₂ (g) + 2 H₂O(g) ∆H° = -802 kJ/mol
Taking into account the definition of enthalpy of a chemical reaction, the quantity of heat released when 5.87 moles of CH₄ are burned is 4,707.74 kJ.
The enthalpy of a chemical reaction as the heat absorbed or released in a chemical reaction when it occurs at constant pressure. That is, the heat of reaction is the energy that is released or absorbed when chemicals are transformed into a chemical reaction.
The enthalpy is an extensive property, that is, it depends on the amount of matter present.
In this case, the balanced reaction is:
CH₄ (g) + 2 O₂ (g) → CO₂ (g) + 2 H₂O(g)
and the enthalpy reaction ∆H° has a value of -802 kJ/mol.
This equation indicates that when 1 mole of CH₄ reacts with 2 moles of O2, 802 kJ of heat is released.
When 5.87 moles of CH₄ are burned, then you can apply the following rule of three: if 1 mole of CH₄ releases 802 kJ of heat, 5.87 moles of CH₄ releases how much heat?
[tex]heat=\frac{5.87 molesof CH_{4}x802 kJ}{1 mol of CH_{4} }[/tex]
heat= 4,707.74 kJ
Finally, the quantity of heat released when 5.87 moles of CH₄ are burned is 4,707.74 kJ.
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https://brainly.com/question/15355361?referrer=searchResultshttps://brainly.com/question/16982510?referrer=searchResultshttps://brainly.com/question/13813185?referrer=searchResultshttps://brainly.com/question/19521752Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Ni and H+ in the balanced reaction? Ni2+(aq) + NH4+(aq) → Ni(s) + NO3-(aq)
In this case, the problem is asking for the balance of a redox reaction in acidic media, in which nickel is reduced to a metallic way and nitrogen oxidized to an ionic way.
Thus, according to the given information, it turns out possible for us to balance this equation in acidic solution by firstly setting up the half reactions:
[tex]Ni^{2+}+2e^-\rightarrow Ni^0\\\\N^{3-}H_4^++3H_2O\rightarrow N^{5+}O_3^-+8e^-+10H^+[/tex]
Next, we cross multiply each half-reaction by the other's carried electrons:
[tex]8Ni^{2+}+16e^-\rightarrow 8Ni^0\\\\2N^{3-}H_4^++6H_2O\rightarrow 2N^{5+}O_3^-+16e^-+20H^+[/tex]
Finally, we add them together to obtain:
[tex]8Ni^{2+}+2N^{3-}H_4^++6H_2O\rightarrow 8Ni^0+2N^{5+}O_3^-+20H^+[/tex]
Which can be all simplified by a factor of 2 to obtain:
[tex]4Ni^{2+}+N^{3-}H_4^++3H_2O\rightarrow 4Ni^0+N^{5+}O_3^-+10H^+\\\\4Ni^{2+}(aq)+NH_4^+(aq)+3H_2O(l)\rightarrow 4Ni(s)+NO_3^-(aq)+10H^+(aq)[/tex]
Hence, the coefficients in front of Ni and H⁺ are 4 and 10 respectively.
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https://brainly.com/question/14965625Thin-layer chromatography explain ?????
Answer:
Explanation:
Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. ... After the sample has been applied on the plate, a solvent or solvent mixture (known as the mobile phase) is drawn up the plate via capillary action.
A chemical property is a change in _____.
density
physical state
hardness
composition of matter
Answer:
composition of an element
study the graph above. In terms of bond energy, which statement is TRUE regarding the energy involved in breaking and making bonds.
a,b,c, or d?
The energy taken in to break the bond is greater than the energy released after the bond is made therefore the reaction is endothermic.
A plot of energy against time is called a reaction profile. The hump in the plot is known as the activation energy of the reaction. It stands as the energy barrier between reactants and products.
Looking at the reaction profile as shown, we can see that more energy is taken in to break the bonds than energy that is given out after making the bonds hence the reaction is endothermic.
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Answer:
the answer is c
Explanation:
usa test prep says so!
A strand of DNA has the following string of bases:
TAACGTCG
What is the order of bases of the RNA molecule that is built from this DNA?
The genetic makeup of the majority of these organisms is either RNA or DNA. For instance, some viruses' genetic material may be RNA whereas others' genetic material may be DNA. RNA is present in the Human Immunodeficiency Virus (HIV), which after adhering to the host cell, transforms into DNA.
DNA is a collection of molecules that is in charge of transporting and passing genetic information from parents to children. A ribonucleic acid called RNA aids in the body's production of proteins. In the human body, new cells are created as a result of this nucleic acid.
Instead of thymine, uracil is present in RNA. All other bases are same as DNA like adenine, guanine and cytosine. The order of bases in RNA is:
UAACGUCG.
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Why we use two different methods for detection of cogulase enzyme ? Or what other reason or what basic different between them?
Chemical properties of mercury hg
Answer:
Mercury has a relatively high vapour pressure and the highest volatility of any metal, vapourizing to become a colourless, odourless gas. The metal is a fair conductor of electricity, but a poor conductor of heat. Mercury's atomic number is 8.
pls help
A 4.0 L sample of gas has a pressure of 300 kPa at 250K. What will the volume be if the pressure is increased to 500 kPa and the temperature is decreased to 200 K?
Answer:A versatile Ideal Gas Laws calculator with which you can calculate the pressure, volume, quantity (moles) or temperature of an ideal gas, given the other three. Free online gas law calculator a.k.a. PV = nRT calculator which accepts different input metric units such as temperature in celsius, fahrenheit, kelvin; pressure in pascals, bars, atmospheres; volume in both metric and imperial units ...
Suppose you have samples of three unknown solids. Explain how you could use their properties to
determine whether or not they are ionic solids.
Using melting and boiling temperature, hardness and electric current passing testing.
Ionic solidsIonic solids are materials that have a strong bond between their ions, thus producing well-defined shapes.
In addition, due to this strong attraction, the boiling and melting temperatures of these materials are very high, in addition to the resistance to breakage presented by them.
Finally, ionic solids are also excellent conductors of electricity.
So, their properties used to determine whether or not they are ionic solids are melting and boiling temperature, hardness and electric current passing testing.
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1.) Calculation: If 9.02 x 1024 particles of vinegar (HC2H3O2)HC2H3O2) are added to 16.5 moles of eggshell (CaCO3) and 6.35 moles g of
calcium acetate is formed. What is the;
(a) theoretical yield,
(b) actual yield and,
(c) percent yield
The theoretical yield of acetate is 2607 g. The actual yield of acetate is 1066.8 g. The percentage yield of acetate is 41%.
If 1 mole of vinegar contains 6.02 x 10^23 particles
x moles of vinegar contains 9.02 x 10^24 particles
x = 1 mole x 9.02 x 10^24 /6.02 x 10^23
x = 15 moles of vinegar
The reaction is as follows;
2HC2H3O2 + CaCO3 -----> Ca(C2H3O2)2 + H2O + CO2
Since 2 moles of vinegar reacts with 1 mole of carbonate
x moles of vinegar reacts with 16.5 moles of carbonate
x = 2 moles x 16.5 moles/ 1 mole
x = 33 moles of vinegar
We can see that the vinegar is the reactant in excess hence the carbonate is the limiting reactant.
Theoretical yield = 16.5 moles x 158 g/mol = 2607 g
Actual yield = 6.35 moles x 158 g/mol = 1066.8 g
Percent yield = 1066.8 g/2607 g × 100/1
= 41%
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Are the 3 right for number 12?
PLEASE HELP!!
ATTACHMENT BELOW
Answer:
read the story
Explanation:
read it and then you will find the answer
outline the properties of alkanes
Answer:
Physical Properties of Alkanes : -
1. Structures of Alkanes
All the carbon atoms present in an alkane are s p 3. Hybridized that is, every carbon atom forms four sigma bonds with carbon or hydrogen atoms. General configuration of alkane is C n H 2 n + 2. They exhibit tetrahedral geometry with a bond angle of 109.47° between them. The methane molecule has a symmetrical tetrahedral structure.2. Solubility of Alkanes
Due to very little difference of electronegativity between carbon and hydrogen and covalent nature of C-C bond or C-H bond, alkanes are generally non-polar molecules. As we generally observe, polar molecules are soluble in polar solvents whereas non-polar molecules are soluble in non-polar solvents. Hence, alkanes are hydrophobic in nature that is, alkanes are insoluble in water. However, they are soluble in organic solvents as the energy required to overcome the existing Van Der Waals forces and generate new Van Der Waals forces is quite comparable.3. Boiling Point of Alkanes
As the intermolecular Van Der Waals forces increase with the increase of the molecular size or the surface area of the molecule we observe. The boiling point of alkanes increases with increasing molecular weight. The straight-chain alkanes are observed to have a higher boiling point in comparison to their structural isomers.4. Melting Point of Alkanes
The melting point of alkanes follows the same trend as their boiling point that is, it increases with an increase in molecular weight. This is attributed to the fact that higher alkanes are solids and it’s difficult to overcome intermolecular forces of attraction between them.It is generally observed that even-numbered alkanes have higher trend in melting point in comparison to odd-numbered alkanes as the even-numbered alkanes pack well in the solid phase, forming a well-organized structure which is difficult to break.Chemical Properties of Alkanes
Alkanes are the least reactive type of organic compound. Alkanes are not absolutely unreactive. Two important reactions that they undergo are combustion, which is the reaction with oxygen and halogenation, which is the reaction with halogens.
1. Combustion
A combustion reaction is a chemical reaction between a substance and oxygen that proceeds with the evolution of heat and light. Alkanes readily undergo combustion reactions when ignited. \When sufficient oxygen is present to support total combustion then carbon dioxide and water are the products.CH2 + 2O2 → CO2 + 2H2O + energy
2C6H14 + 19O2 → 12CO2 + 14H2O + energy
The exothermic nature of alkane combustion reactions explains the extensive use of alkanes as fuels. Natural gas, used in home heating is predominantly methane.2. Halogenation
Halogenation of an alkane produces a hydrocarbon derivative in which one or more halogen atoms have been substituted for hydrogen atoms. An example of an alkane halogenation reaction is
CH3 - CH3 + Br2 → CH3 - CH2 - Br + HBr
Alkane halogenation is an example of a substitution reaction a type of reaction that often occurs in organic chemistry. A general equation for the substitution of a single halogen atom for one of the hydrogen atoms of an alkane is
R - H + X2 → R - X + H - X
Explanation:
What is the density of a sponge that has a mass of 100g and a volume of 10 mL?
Answer:
10
Explanation:
Equation: d = m/v
100/10 = 10
The group of elements that make up the smallest percentage of the periodic table are the
Answer:
Explanation:wwwwwwwwwwwwwwwwwwww
answer this please ......................
Answer:
River esk the third one is righttt
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Water waves in a small tank are 6.0 cm long. They pass at a given point at a rate of 4.8 waves per second. What is the speed of the wave?
Answer:, Correct option is 0.288m/s
Explanation:
The relationship between the velocity of the wave, its wavelength and frequency is given by the formula
Wavelengthλ=
Frequency(ν)
Speed(v)
,
where, v - velocity of the wave
λ - wavelength of the wave
f - frequency of the wave.
In the question it is given that the frequency is 4.8 Hz and the wavelength is 6.0 cm, that is, 0.06 meters.
The velocity of the sound is calculated as follows.
v=f×λ=4.8 Hz×0.06 m=0.288 m/s
Hence, the speed of the water wave is 0.288 m/s.
Ionic compounds in own words
an ionic compound is made of two or more elements held by a strong electrostatic force. metal atoms lose electrons to become positive ions, and non metals gain electrons to become negative ions. ionic bonding occurs between metals and non metals
Disadvantage and advantage of iodine ?
- umoren sŭm..
THE ADVANTAGE OF IODIN
IODINE CAN LEAD TO GOITER AND OTHER THYROID PROBLEMS.THE DISADVANTAGE OF IODIN
IODIN MAY LEAD TO THYROIDITIS AND THYROID PAPILLARY CANCERHow could you tell if a substance has undergone a physical change or a chemical one?
Answer: Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
A physical change is are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
A mixture of solids containing a ketone, a carboxylic acid, and an amine, are dissolved in DCM. What is the best way to begin an extraction to separate the amine from the mixture
There are different ways of extraction. The best way to begin an extraction to separate the amine from the mixture is to extract with dilute NaOH.
An acid-base extraction is often used in the extraction of carboxylic acids from the organic layer and thereafter into the aqueous layer.NaOH is known to be the most common compound that is used to convert a carboxylic acid into its more water-soluble ionic carboxylate form.
But if the mixture has a compound that you want, and that can react with NaOH, another milder base such as sodium bicarbonate is preferably used.
See full question below
A mixture of solids containing a ketone, a carboxylic acid, and an amine, are dissolved in DCM. What is the best way to begin an extraction in order to separate the carboxylic acid from the mixture?
A) Extract with dilute NaOH
B) Extract with dilute HCl
C) Extract with dichloromethane
D) Extract with water
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What is the coefficient for O2 in the balanced version of the following chemical equation: C2H4+O2→CO2+H2O
Answer:
3
Explanation:
Here's the balanced equation;
C2H4 + 3O2 → 2CO2 + 2H2O
C ⇒2 C ⇒1 x 2 = 2
H ⇒4 H ⇒2 x 2 = 4
O ⇒3 x 2 = 6 O ⇒ (2 x 2) + (2 x 1) = 6
The coefficient that has been added as the coefficient to O2 is 3.
C2H4 + 3O2 → 2CO2 + 2H2O.
the given equation has 2oxygen atoms on the reactant side and 3 oxygen atoms on the product side
so to make it equal we have to add 3 as coefficient of O2 on the reactant side.
Therefore the correct answer to the equation C2H4 + 3O2 → 2CO2 + 2H2O is 3.
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HELP ME OUT PLEASE!!!!!!!!
A chemical reaction in which calcium carbonate (CaCO3) is decomposed (broken down) results in the production of two simpler compounds. (See diagram) What mass of Calcium Carbonate (CaCO3) to the nearest hundredth of a gram, is broken down in this reaction?
A) 28 00g
B) 21979
C) 49.979
D) 50.000
Answer:
49.979
Explanation: