Answer:
A piece of metal is placed in water and produces sparks and gas.
The sign of a chemical reaction has occurred is a piece of metal is placed in water and produces sparks and gas. The correct option is B.
What is a chemical reaction?Chemical changes, often known as chemical reactions, are the transformation of one or more compounds into one or more brand-new, separate substances. In other words, a chemical change is a process based on atomic rearrangement.
Metal is malleable and luster substance. They are gold, silver, magnesium, etc. They are present in the periodic table. Furthermore, they are highly reactive and soft.
A chemical reaction is happening in the reaction of water when it produces a spark or gas when reacting with another substance.
Thus, the correct option is B. A piece of metal is placed in water and produces sparks and gas.
To learn more about chemical reactions, refer to the link:
https://brainly.com/question/14929452
#SPJ2
What is the mass of sodium thiosulphate pentahydrate required to prepare 250cm3 of a 0.14mol/dm3 solution
Answer:
Strength of the sodium thiosulphate solution to be produced is 0.150M= 0.150mol/L×248.2g/mol=37.23g/L. So 1L or 1000 mL solution ...
Missing: 0.14mol/dm3 | Must include: 0.14mol/dm3
Answer:
Mass = 8.68g
Explanation:
Mass = Concentration × Molar mass × Volume (in dm^3)
but, concentration = 0.14 mol/dm^3.
volume = 250 cm^3 = 0.25 dm^3.
Molar mass of Na2S2O3 . 5H2O
= (2×23)+(2×32)+(3×16)+(5×18)
= 248 g/mol
hence, mass = 0.14 × 248 × 0.25
Mass = 8.68 g.
I HOPE IT'S OK?
While in Europe, if you drive 109 km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per liter and your car's gas mileage is 22.0 mi/gal ? Assume that 1euro=1.26dollars.
Answer:
The amount is [tex]x = 113.3 \ dollars[/tex]
Explanation:
From the question we are told that
The distance traveled per day is [tex]l = 109\ km = \frac{109}{1.609} = 67.74 \ mi[/tex]
The cost of one liter is [tex]c = 1.10 \ euros/liter = 1.10 * 1.26 = 1.36 \ dollars/liter[/tex]
The car's gas mileage is [tex]b = 22.0 \ mi/gal[/tex]
Generally the amount of distance covered in one week is evaluated as
[tex]z = 67.74 * 7[/tex]
[tex]z = 474.18 \ mi[/tex]
The amount of gas used in one week by the car is mathematically represented as
[tex]k = \frac{ z}{ b}[/tex]
=> [tex]k = \frac{ 474.18}{ 22}[/tex]
=> [tex]k = 22 \ gal[/tex]
converting to liters
[tex]k = 22 * 3.78541=83.28 \ liters[/tex]
Thus the amount spent on gas in one week is
[tex]x = k * c[/tex]
=> [tex]x = 83.28 * 1.36[/tex]
=> [tex]x = 113.3 \ dollars[/tex]
write the name of this structure
Answer:
The name of the compound is:
4–bromo–5,5–dichloro–hex–3–ene–1–yne
Explanation:
To the above compound, we simply do the following:
1. Identify the functional group of the compound.
2. Locate the longest continuous carbon chain. This gives the parent name of the compound.
3. Identify the substituent group attached.
4. Give the substituents the lowest possible count alphabetically.
5. Combine the above to obtain the name of the compound.
Now, we shall determine the name of the compound as follow:
1. The compound has carbon to carbon triple bond (C≡C) yne and carbon to carbon double bond (C=C) ene.
2. The longest continuous carbon chain is 6 i.e hexane.
3. The substituents group attached are:
i. Bromine (bromo), Br
ii. Chlorine (Chloro), Cl
4. In counting, ene comes before yne. But in this case, ene assumes same position from either side, So we shall consider counting from the side that gives yne the lowest count. Thus, ene is at carbon 3 and yne is at carbon 1. Therefore,
i. Bromo, Br is at carbon 4.
ii. Chloro, Cl appears twice and both are at carbon 5.
5. The name of the compound is:
4–bromo–5,5–dichloro–hex–3–ene–1–yne.
Using her new telescope Ashley discovers a spherical meteor passing between the earth and the moon and measures it’s radius as 3 kilometers how many cubic kilometers are in the meteor
Answer:
113 km³
Explanation:
Step 1: Given data
Radius of the meteor (r): 3 km
Step 2: Calculate the volume (V) of the meteor
The meteor is spherical. Given the radius (r), we can calculate the volume of a sphere using the following expression.
V = 4/3 × π × r³
V = 4/3 × π × (3 km)³
V = 4/3 × π × 27 km³
V = 113 km³
The volume of the meteor is 113 km³.
Sulphuric acid decomposes into H2O and SO3. H2SO4(l)⟶H2O(g)+SO3(g) If 10.0 g of sulphuric acid is completely decomposed in a closed container with a total volume of 3.00 L and no air at 350∘C, what will the total pressure in the container be in atmospheres? Assume the volume of the liquid is negligible. Answer should have three significant figures.
Answer:
3.48 atm
Explanation:
The first step is to determine the number moles of sulfuric acid. To do this find the molar mass of sulfuric acid.
Molar Mass of H2SO4 = (1 g/mol*2) + (32 g/mol) + (16 g/mol * 4) = 98 g/mol
Then divide the mass of sulfuric acid by the molar mass of the sulfuric acid to get the number of moles of sulfuric acid.
(10 g)/(98 g/mol) = 0.10204 mol
Then use the molar ratios to determine the moles of gas produced. In this case all of the ratios are 1 to 1 meaning that 0.10204 mol of H2SO4 produces 0.10204 mol of H2O and 0.10204 mol of SO3. That means that 0.2041 moles of gas are produced as a result of the reaction.
The next thing to do is to convert the temperature to Kelvin since gas equations need Kelvin. To do this add 273.15.
350 degrees C + 273 = 623.15 K
Now the PV=nRT can be used and when solving for pressure the equation can be written P=nRT/V.
P = pressure and is the unknown
V = volume and is 3.00 L
n = moles of gas and is 0.2041 mol
R = gas constant and is 0.08205 L atm/mol K
T = temperature and is 623.15 K
P = (0.2041 mol * 0.08205 L atm/mol K * 623.15 K) / 3.00 L
P = 3.4785 atm which is 3.48 atm when rounded to three significant figures
I hope this helps. Let me know if anything is unclear.
The total pressure of the container has been 3.48 atm.
In the decomposition of 10 grams of sulfuric acid, the moles of sulfuric acid has been:
Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]
Moles of sulfuric acid = [tex]\rm \dfrac{10\;g}{98\;g/mol}[/tex]
Moles of sulfuric acid = 0.1024 moles.
The balanced chemical equation for the reaction results in the formation of 1 mole of water and 1 mole of [tex]\rm SO_3[/tex]. Thus, the decomposition of 1 mole of gas produces 2 moles of the product.
The moles of the product by decomposition of 0.1024 moles of sulfuric acid has been:
1 mole sulfuric acid = 2 moles product
0.1024 moles sulfuric acid = 0.2048 moles product.
From the ideal gas equation:
PV = nRT
P = pressure
V = volume = 3 L
n = moles = 0.2048 moles
R = constant = 0.08205 L atm/mol K
T = temperature = 623.15 K
Substituting the values:
Pressure × 3 L = 0.2048 mol × 0.08205 L atm/mol K × 623.15 K
Pressure = 3.4785 atm.
The pressure of the system has been 3.48 atm.
For more information about the pressure of the system, refer to the link:
https://brainly.com/question/908756
You take the following measurements in a density determination according to the procedure in part 1 using a triple beam balance and graduated cylinder. what is the density of liquid to be correct number of significant figure.
weight of cylinder + 19.7 mL liquid = 58.20 g
weight of cylinder + 10.2 mL liquid = 49.50 g
Answer:
0.916g/mL is the density of the liquid
Explanation:
Density is defined as the mass of a substance in a determined volume (Usually grams per mililiter).
The only difference between the first and second measurements is the volume of the liquid:
19.7mL - 10.2mL = 9.5mL is the difference in volume of the liquid between first and second weighs.
This volume, 9.5mL, weighs:
58.20g - 49.50g = 8.7g
As density is the ratio between mass in grams and volume in mL:
Density: 8.7g / 9.5mL
0.916g/mL is the density of the liquidwhich of the following molexules would you predict to be most polar? i. co2 ii. cf4 iii. both have the same molecular polarity why?
Answer:
iii. both have the same molecular polarity
Explanation:
Both CF4 and CO2 are nonpolar molecules.
CF4 is a tetrahedral molecule, the compound is highly symmetrical hence the individual dipole moments due to the four C-F bonds cancel out thereby making the molecule to be nonpolar.
Similarly, the direction of the two dipoles in CO2 cancel out since they are directed in opposite directions making the molecule nonpolar.
A student completes a titration of an unknown diprotic acid. In this experiment, 0.79 g of the acid is dissolved in 250.0 mL of water. It requires 13.48 mL of 1.0 M NaOH to reach the second equivalence point. What is the molar mass of the acid?
Answer:
117.21g/mol
Explanation:
The reaction of a diprotic acid, H₂X with NaOH occurs as follows:
H₂X + 2NaOH → Na₂X + 2H₂O
Where 2 moles of NaOH reacts per mole of the diprotic acid
Knowing the moles of NaOH and the chemical equation we can determine the moles of the diprotic acid. With the moles and its mass we can find the molar mass of the acid, thus:
Moles of the diprotic acid:
To reach the equivalence point, it requires 13.48mL = 0.01348L of 1.0M NaOH. That is:
0.01348L × (1mol NaOH / L) = 0.01348 moles NaOH
As 2 moles of NaOH reacts per mole of the diprotic acid, moles of the acid are:
0.01348moles NaOH × (1mol H₂X / 2mol NaOH) = 0.00674 moles of H₂X
Molar mass:
The molar mass of a compound is the ratio between the mass you have per mole. As mass is 0.79g and moles are 0.00674moles, molar mass is:
Molar mass: 0.79g / 0.00674mol =
117.21g/molHow many mg does a 643 kg sample contain?
Answer:
[tex]6.43x19^8mg[/tex]
Explanation:
Hello,
In this case, this unit conversion is performed by knowing that 1 kg of mass contains 1000 g and 1 g contains 1000 mg, therefore, the result is:
[tex]643kg*\frac{1000g}{1kg} *\frac{1000mg}{1g}\\ \\=6.43x10^8mg[/tex]
Regards.
What do all living things need to survive?
Answer:
air,water,and food.
Explanation:
Some animals need to obtain their energy from plants.
HELP! pH = -log10[H+]. If pH 3.5 what is [H+]?
Calculate the cell potential, the equilibrium constant, and the free energy change for
Ba(s)+Mn2+(aq,1M)→Ba2+(aq,1M)+Mn(s)
Given the following E degree values:
Ba2+(aq)+2e→Ba(s), E degree=−2.90V
Mn2+(aq)+2e→Mn(s),E degree=0.80V
Answer:
Explanation:
Ba(s) + Mn²⁺ (aq,1M) → Ba²⁺ (aq,1M) + Mn(s)
Ba⁺²(aq) +2e → Ba(s) , E° = −2.90 V
Mn⁺²(aq) +2e → Mn(s), E⁰ =0.80 V
Anode reaction :
Ba(s) → Ba⁺²(aq) +2e E° = −2.90 V
Cathode reaction :
Mn⁺²(aq) +2e → Mn(s) E⁰ =0.80 V
Cell potential = Ecathode - Eanode
Ecell = .80 - ( - 2.90 )
Ecell = 3.7 V .
equilibrium constant ( K ) :
Ecell = .059 log K / n
n = 2
3.7 = .059 log K / 2
log K = 125.42
K = 2.63 x 10¹²⁵ .
Free energy change :
ΔG = - n F Ecell
= - 2 x 96500 x 3.7
= 714100 J
= 7.141 x 10⁵ J .
When 36.5g Of NaCL(s) is added to enough water to make 550.0 ml of solution, what is the molarity of the solution?
Answer:
1.1442 moles| litre,NaCl
Explanation:
RAM:56g|mole
number of moles=36.5g÷58g|mole =0.6293moles
0.6293 is contained in 550ml
=1000ml
[1000×0.6293]÷550 =1.1442moles| litre,NaCl
A reaction occurs via the following sequence of elementary steps. What is the reaction intermediate?
1st step: A + 2B → 2C
2nd step: 2C → D
Answer:
C is the reaction intermediate.
Explanation:
A reaction intermediate is a molecular structure that is formed during the reaction but then is converted in the final products.
Usually, these reaction intermediates are unestable and, for that reason, the lifetime of these structures is low.
In the reaction, you can see in the first step C is produced, but also, in the second step reacts producing D. As is produced and, immediately consumed,
C is the reaction intermediate.What is the empirical formula of a hydrocarbon if complete combustion or 2.900 mg of the hydrocarbon produced 9.803 mg of CO2 and 2.006 mg of H2O? Be sure to write C first in the formula.
Answer:
The empirical formula of the hydrocarbon is CH.
Explanation:
The following data were obtained from the question:
Mass of hydrocarbon = 2.9 mg
Mass of CO2 = 9.803 mg
Mass of H2O = 2.006 mg
Next, we shall determine the mass of carbon (C) and hydrogen (H) in the compound since hydrocarbon contains carbon and hydrogen only.
This is illustrated below:
Molar mass of CO2 = 12 + (16x2) = 12 + 32 = 44 g/mol
Mass of CO2 = 9.803 mg
Mass of C in the compound =?
Mass of C in the compound =
12/44 x 9.803
= 2.674 mg
Molar mass of H2O = (2x1) + 16 = 2 + 16 = 18 g/mol
Mass of H2O = 2.006 mg
Mass of H in the compound =
2/18 x 2.006
= 0.223 mg
Finally, we shall determine the empirical formula of the hydrocarbon as follow:
Carbon (C) = 2.674 mg
Hydrogen (H) = 0.223 mg
Divide by their molar mass
C = 2.674 /12 = 0.223
H = 0.223 / 1 = 0.223
Divide both side by the the smallest
C = 0.223/0.223 = 1
H = 0.223/0.223 = 1
Therefore, the empirical formula of the hydrocarbon is CH.
A mixture of glycine, alanine, aspartic acid, glutamic acid, leucine, lysine, histidine, asparagine, and phenylalanine are put into an electrophoresis apparatus, with the buffer pH=6.5. Sort each amino acid according to its charge in the buffer with a pH of 6.5.
a. Glycine
b. Alanine
c. Glutamic acid
d. Alanine aspartic acid
e. Leucine
f. Histidine asparagine
g. Phenylalanine
h. Lysine
Answer:
Positively charged: Lysine, Histidine
Negatively charged: Asparagine, Phenylalanine, Glutamatic acid, Alanine, Glycine, Leucine, Aspartic acid
Explanation:
The charge of an amino acid in solution is determined by its isoelectric point, pI, which is the characteristic pH in which the net electric charge of the amino acid is zero. In solutions of pH below the isoelectric point, the amino acid has a net positive charge whereas in solutions with pH above isoelectric point, the net charge on the amino acid is negative.
In a buffer solution of pH 6.5, the following charges are present in the amino acids given:
Positively charged: Lysine (pI = 9.74), Histidine (pI = 7.59)
Negatively charged: Asparagine (pI = 5.07), Phenylalanine (pI = 5.48), Glutamatic acid (pI = 3.22), Alanine (pI = 6.01), Glycine (pI = 5.97), Leucine (pI = 5.98), Aspartic acid (pI = 2.77)
If you add enzyme to a solution containing only the product(s) of a reaction, would you expect any substrate to form?
a. Yes, because the enzyme reduces the standard free energy change for the reaction.
b. No, because the enzyme lowers the transition state energy barrier.
c. No, because product inhibits the enzyme.
d. No, because enzymes catalyze only the forward reaction.
e. Yes, because the reaction proceeds backwards until equilibrium is reached.
Answer:
e
Explanation:
Provided the reaction that leads to the formation of the products can proceed in both forward and backward directions, the correct answer would be yes because the reaction will proceed backward until equilibrium is reached.
For a reaction that can proceed both forward and backward, the addition of a catalyst increases the rate of reaction in both directions based on the fact that a catalyst cannot alter the equilibrium of a reaction.
Hence, if an enzyme is added to the product of a reaction that has the potential to proceed in both forward and reverse reactions, a substrate would be expected to form because the reaction will proceed backward until an equilibrium is reached.
The correct option is e.
what subatomic particles are found in the nucleus of an atom
Answer:
Explanation:
The subatomic particles of protons and neutrons are found in the nucleus of an atom. Protons are particles with a positive charge, while neutrons have no charge. Electrons, which have a negative charge, are particles that can found orbiting outside the nucleus of an atom.
Answer: protons and neutrons
Explanation:
The energy produced when nucleons fuse together is called the: Select the correct answer below:
a. strong nuclear force
b. nuclear fusion energy
c. nuclear binding energy
d. none of the above
Answer:
Option C (nuclear binding energy) is the appropriate choice.
Explanation:
At either the nuclear scale, the nuclear binding energy seems to be the energy needed to remove and replace a structure of the atom itself into the characterize elements (to counteract the intense nuclear arsenal). Nuclear warheads (bargaining power) bind everything together neutrons as well as protons within an elementary particle.Some other options in question aren't relevant to the particular instance. So that the option preceding will also be the right one.
The purpose of the best-fit line on an experimental scatterplot is to:_______.
a. The best-fit line allows us to predict behavior between measured data using its slope.
b. Ignore data points that don't fit the line.
c. Determine individual slopes between each set of data points
Answer: a. The best-fit line allows us to predict behavior between measured data using its slope.
Explanation:
A line of best fit is drawn through a scatter-plot to determine the direction of an relation between two quantities.
The line of best fit can be used to make prediction for the dependent variables.
Hence, the purpose of the best-fit line on an experimental scatter-plot is to predict behavior between measured data using its slope.
Hence, the correct option is "a."
Why are plastic containers preferred to glass containers for storing chemicals in the laboratory?
How is safety achieved during scientific investigations?
Answer investment
Explanation: you have to have saftey while you still do science
Explain why animals that come out at night have lots of rods in their retina
Answer:
Nocturnal animals, such as owls, tend to have wide pupils and several rod cells in their retina because wide pupil allow more light to enter the eyes and the rods cells in the retina are sensitive to dim light and are vital for night vision.
Imagine that you are in the laboratory and find broken glass on your
workbench. Describe what you would do to handle this situation.
Your answer
Please help
Answer:
Laboratory is a place where all the experiments are to be done by the students or teachers so it should be safe and clean. I will not allow anyone inside until the glass peaces are cleaned
Some molecules such as iodine have two atoms to make up the substance, while others have thousands. A molecule of sugar has 45 atoms to make up the substance. If a sugar crystal has 1000 molecules, how many atoms are present?
Answer:
45000 atoms
Explanation:
From the question given above, we were told that a molecule of a sugar is made up of 45 atoms. This implies that:
1 molecule of sugar = 45 atoms
With the above idea in mind, we can obtain the number of atoms present in 1000 molecules of the Sugar as follow:
1 molecule of sugar = 45 atoms
Therefore,
1000 molecules of sugar = 1000 × 45 = 45000 atoms.
Therefore, there are 45000 atoms present in 1000 molecules of the sugar.
im just typing so u can give them brainliest :)
liquid water has the density of 1000.0kg/m^3. Calculate the volume occupied by 0.250kg of liquid water.
Answer:
[tex]V=2.5x10^{-4}m^3\\\\V=0.25L[/tex]
Explanation:
Hello,
In this case, since the density is defined as the degree of compactness a substance has and is mathematically defined as:
[tex]\rho =\frac{m}{V}[/tex]
Thus, for this problem, as we know both the density and mass of water we can compute the volume as shown below:
[tex]V=\frac{m}{\rho}=\frac{0.250kg}{1000.0kg/m^3}\\ \\V=2.5x10^{-4}m^3\\\\V=0.25L[/tex]
Best regards.
A student measures the molar solubility of iron(II) carbonate, FeCO3, in a water solution to be 6.06 × 10-6 M. Based on her data, the solubility product constant for this compound is:______.
a. 8.90 × 10-27
b. 1.21 × 10-5
c. 3.67 × 10-11
d. 1.06 ×10-25
e. 8.17 × 10-27
Answer:
The correct answer is c. 3.67 × 10⁻¹¹
Explanation:
The dissociation equilibrium and ICE table for FeCO₃ is the following:
FeCO₃ (s) ⇄ Fe²⁺(aq) + CO₃²⁻(aq)
I 0 0
C +s +s
E s s
At equilibrium, the solubility product contant (Ksp) expression will be:
Ksp= [Fe²⁺] x [CO₃²⁻]= s x s = s²
Given: s= 6.06 x 10⁻⁶ M, we calculate Ksp as follows:
Ksp= s²= (6.06 x 10⁻⁶ M)²= 3.67 x 10⁻¹¹
Thus, from the given options the correct is c. 3.67 × 10⁻¹¹
Hydrangea is a flower that presents in a variety colors including blue, white and pink. The color of some varieties of
hydrangea flowers can be controlled by the gardener growing the plant in a container and carefully regulating the pH. In
some instances aluminum sulfate, Al2(SO4)3, must be added as well. Perform an on-line search to identify what pH range
favors pink and blue color petals on hydrangea flowers. Also comment on the role of aluminum sulfate in determining the
color of the flower.
Answer:
Bigleaf hydrangeas are blue if the pH is between 5.0 and 5.5. The flowers
turn pink when the pH gets around 6.0. The flower color is dependent on
the concentration of aluminum ions (Al+++) in the soil. Aluminum is more
available to the plant when the soil is acidic, less available when the soil is
alkaline.The color of the cultivar called “Endless Summer” of H. macrophylla depends
on soil pH. Red or pink blooms result from neutral or basic soil (pH 7 and
above), whereas blue blooms indicate acidic conditions (pH less than 7).
Calculate the MASS if the density is 2.34 g/mL and the volume is 12.50 mL.
Answer:
mass = 29.25 gExplanation:
The denisty of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
Making mass the subject we have
mass = Density × volumeFrom the question
Density = 2.34 g/mL
volume = 12.50 mL
Substitute the values into the above formula and solve for the mass
That's
mass = 2.34 × 12.50
We have the final answer as
mass = 29.25 gHope this helps you
If the initial concentrations of A and B are 0M each, and the initial concentrations of C and D are 1.6M each, and Kc=4.7, what is the equilibrium concentration of A?
Answer:
[tex][A]_{eq}=0.095M[/tex]
Explanation:
Hello,
In this case, for the reaction:
[tex]A+B\rightleftharpoons C+D[/tex]
It is clear that the equilibrium expression is:
[tex]Kc=\frac{[C][D]}{[A][B]}[/tex]
Nevertheless, since the initial concentrations of both A and B are 0 M and C and D 1.6 M, we should invert the reaction:
[tex]C+D\rightleftharpoons A+B[/tex]
Thereby the equilibrium expression is also inverted:
[tex]Kc=\frac{[A][B]}{[C][D]}[/tex]
Which can be written in terms of the reaction extent and initial concentrations as shown below:
[tex]\frac{1}{Kc} =\frac{x*x}{([C]_0-x)([D]_0-x)}\\\\\frac{1}{0.47}= \frac{x*x}{(1.6-x)(1.6-x)}[/tex]
Hence, solving for [tex]x[/tex] we obtain:
[tex]x=0.095M[/tex]
In such a way, the equilibrium concentration of A is:
[tex][A]_{eq}=x=0.095M[/tex]
Best regards.
The equilibrium concentration of A will be "0.095 M". To understand the calculation, check below.
EquilibriumAccording to the question,
Initial concentration for A and B = 0 M
For C and D = 1.6 M
Kc = 4.7
Here the reaction:
→ A + B [tex]\rightleftharpoons[/tex] C + D
We know the expression,
Kc = [tex]\frac{[C][D]}{[A][B]}[/tex]
By inverting the reaction,
→ C + D [tex]\rightleftharpoons[/tex] A + B
Kc = [tex]\frac{[A][B]}{[C][D]}[/tex]
By substituting the values,
[tex]\frac{1}{Kc}[/tex] = [tex]\frac{x\times x}{([C]_0 -x)([D]_0 -x)}[/tex]
= [tex]\frac{x\times x}{(1.6 - x)(1.6 -x)}[/tex]
x = 0.095 M ([tex][A]_{eq}[/tex])
Thus the above approach is correct.
Find out more information about equilibrium here:
https://brainly.com/question/19340344