Which method do you think the suspects used to make the coins, additive plating or displacement plating?
Answer:
See explanation
Explanation:
Electroplating is a method used to coat a metal on top of another metal for various purposes.
Additive plating involves the coverage of a metal surface by another metal. To make the coins, the suspects had to coat the required coinage metal on another metal called the base metal so as to produce the coin.
Hence the method used must be additive plating method.
Assuming the volume is constant, if a gas has an
initial pressure of 84.0 kPa at 30.0°C, what would
the new pressure be at 240.0°C? (Round to the
nearest whole number)
kPa
DONE
1) Intro
2 of 3
Answer:
672kP
Explanation:
Equate the initial pressure with respect the first temperature. The unknown pressure to the second temperature and you cross multiply
Answer: 142kPa.
Explanation:got it right on edge 2020
Can metals have covalent radius and van der Waal's radius instead of metallic radius?
Explanation:
Whether you choose to use van der Waals radii or metallic radii as a measure of the atomic radius, for metals the ionic radius is smaller than either, so the problem doesn't exist to the same extent. It is true that the ionic radius of a metal is less than its atomic radius (however vague you are about defining this).
Whether you choose to use van der Waals radii or metallic radii as a measure of the atomic radius, for metals the ionic radius is smaller than either, so the problem doesn’t exist to the same extent. It is true that the ionic radius of a metal is less than its atomic radius (however vague you are about defining this).
HOPE SO IT HELPS YOU
What is the speed of a wave that has a frequency of 220 Hz and a wavelength
of 0.39 m?
A. 0.002 m/s
B. 564 m/s
C. 85.8 m/s
D. 0.01 m/s
Answer:
12d
Explanation:
List two possible steps where impurities may be gained, which would appear to be an increase in copper
yield (why you may get more than 100% of the copper back at the end). Be specific about the steps and
how they might add impurities.
Answer:
i) During washing
ii) During Measurement
Explanation:
The two possible steps are :
i) During washing : during the washing method the residue may be not completely dried out and this residue ( water) will add up to the final product ( copper yield ) and this kind of error is called human error.
ii) During measurement : If the weighing instrument is faulty there might be addition in value of the final copper yield which will see the final yield value > 100% . this error occurs when the initial value and final value is been weighed
Given the reaction:
Sn2+ (aq) + 2Fe3+ (aq) → Sn4+ (aq) + 2Fe2+ (aq)
The oxidizing agent in this reaction is?
A Sn2+
B Fe3+
C Sn4+
D Fe2+
Write the net ionic equation for this precipitation reaction. Include physical states. 2LiCl(aq)+Pb(CH3COO)2(aq)⟶PbCl2(s)+2LiCH3COO(aq)
Answer:
[tex]{ \bf{ 2 Cl{}^{ - } _{(aq)} + Pb {}^{2 + } _{(aq)} \: ⟶ \: PbCl _{2(s)}}}[/tex]
Calculate the number of moles of NaOH in an aqueous solution of 36 cm3 of 0.1 mol dm−3.
PLSS EXPLAIN WHAT YOU DO I DONT GET IT
Answer: The number of moles of NaOH is 0.0036 moles
Explanation:
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}[/tex] .....(1)
Given values:
Molarity of NaOH = [tex]0.1mol/dm^3=0.1mol/L[/tex] (Conversion factor: [tex]1L=1dm^3[/tex]
Volume of the solution = [tex]36cm^3=36 mL[/tex] (Conversion factor: [tex]1mL=1cm^3[/tex]
Putting values in equation 1, we get:
[tex]0.1=\frac{\text{Moles of NaOH}\times 1000}{36}\\\\\text{Moles of NaOH}=\frac{0.1\times 36}{1000}=0.0036mol[/tex]
Hence, the number of moles of NaOH is 0.0036 moles
Calculate the percent water in ZnSO4.7 H20. Show your work.
Answer:
43.8%
Explanation:
Find the sum of the relative atomic mass of all the elements constituting the compound, which is known as the relative formula mass;
[tex]M_{r} = Relative \ formula \ mass \\\\M_{r} \ of \ ZnSO_{4} = 65.4 + 32.1 + 4(16) \\\\M_{r} \ of \ ZnSO_{4} = 97.5 + 64 \\\\M_{r} \ of \ ZnSO_{4} = 161.5 \\\\M_{r} \ of \ H_{2}O = 18 \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 161.5 + 7(18) \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 287.5[/tex]
Then, divide the relative formula mass of all the water by that of the whole compound
w = % water
[tex]w = \frac{7(18)}{287.5} * 100 \\\\w = 0.43826... * 100\\\\w = 43.826...[/tex]
w = 43.8%
A neutral atom has 37 electrons. How many protons does the
atom have?
a more than 37 protons
bless than 37 protons
C exactly 37 protons
d it is impossible to know without more information
Answer:
It's answer is c) exactly 37 protons
Answer:
C) , Exactly 37 protons.
Explanation:
Remember the electrons have a negative charge, so to make a atom with 37 electrons neutral, you will need the same amount of the opposite type. That means you need 37 protons.
Complete the following statements to describe solids, liquids, and gases. Select the correct answer fror
A solid
A liquid
A gas
va definite volume and
a definite volume and
a definite volume and
v
a definite shape.
a definite shape.
a definite shape.
Answer:
solid is definite volume and shape
liquid is a definite volume but not a definite shape because it can move around and fit into different shapes, like on different water bottles.
gas is not a definite volume and not a definite shape because gas particles can expand and spread out which affects both volume and shape
An aqueous sodium acetate, NaC2H3O2 , solution is made by dissolving 0.395 mol NaC2H3O2 in 0.505 kg of water. Calculate the molality of the solution.
Answer: The molality of [tex]NaC_2H_3O_2[/tex] solution is 0.782 m
Explanation:
Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg. The formula used to calculate molality:
[tex]\text{Molality of solution}=\frac{\text{Moles of solute}}{\text{Mass of solvent (in kg)}}[/tex] .....(1)
Given values:
Moles of [tex]NaC_2H_3O_2[/tex] = 0.395 mol
Mass of solvent (water) = 0.505 kg
Putting values in equation 1, we get:
[tex]\text{Molality of }NaC_2H_3O_2=\frac{0.395mol}{0.505kg}\\\\\text{Molality of }NaC_2H_3O_2=0.782m[/tex]
Hence, the molality of [tex]NaC_2H_3O_2[/tex] solution is 0.782 m
How many molecules are present in this sample
0.423 mol co
In what method Copper sulphate solution change blue to colourless ??
Answer: When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green.
How would the equilibrium of the reaction below be affected if the temperature decreased?
Answer:
A. More O2, SO2, and SO3 would be produced.
Explanation:
The decomposition of carbon disulfide to carbon monosulfide and sulfur is first order with k=2.8 ×10^-7 at 1000°C .What is the half-life of this reaction at 1000°C?
Answer:
2.5×10⁶ s
Explanation:
From the question given above, the following data were obtained:
Rate constant (K) = 2.8×10¯⁷ s¯¹
Half-life (t½) =?
The half-life of a first order reaction is given by:
Half-life (t½) = 0.693 / Rate constant (K)
t½ = 0.693 / K
With the above formula, we can obtain the half-life of the reaction as follow:
Rate constant (K) = 2.8×10¯⁷ s¯¹
Half-life (t½) =?
t½ = 0.693 / K
t½ = 0.693 / 2.8×10¯⁷
t½ = 2.5×10⁶ s
Therefore, the half-life of the reaction is 2.5×10⁶ s
The frequency of an X ray is 6.5 x 1018 Hz. What is the X ray’s wavelength? .
Answer:
The X ray’s wavelength is 4.61*10⁻¹¹ m
Explanation:
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).
Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).
The propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave's disturbance propagates along its displacement. Relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:
v = f * λ.
In this case:
The frecuency f= 6.5*10¹⁸ Hz The speed v=c= 3*10⁸ [tex]\frac{m}{s}[/tex]Replacing:
3*10⁸ [tex]\frac{m}{s}[/tex]= 6.5*10¹⁸ Hz* λ
Solving:
[tex]wavelength= \frac{3*10^{8} \frac{m}{s} }{6.5*10^{18} Hz}[/tex]
λ= 4.61*10⁻¹¹ m
The X ray’s wavelength is 4.61*10⁻¹¹ m
Which fundamental force(s) can act over very long distances?
A. Gravity and electrostatic force
B. Strong nuclear force and weak nuclear force
C. Gravity only
D. Electrostatic force and strong nuclear force
Answer:
C. Gravity only
Explanation:
CHEMISTRY HW... DUE in 2.5 hours! HELP!!!!
Answer:
The final temperature aluminium-water system is 24° C
Explanation:
Heat energy, H = mcθ
Where m is mass of substance, c is specific heat capacity, θ is temperature difference
Using the principle, Heat lost = Heat gained
Let the final temperature of the aluminium-water system be Tfinal
Heat lost by aluminium, H₁ = -m₁c₁(Tfinal - 40)
Heat gained by water, H₂ = m₂c₂(Tfinal -21)
Heat lost by aluminium, H = -[30 × 0.21 × (Tfinal - 40)]
H₁ = -6.3Tfinal + 252
Heat gained by water, H₂ = 50 × 1.0 × (Tfinal - 21)
H₂ = 5Tfinal - 21
Equating H₁ and H₂
-6.3Tfinal + 252 = 5 Tfinal - 21
5Tfinal + 6.3Ffinal = 252 + 21
11.3 Tfinal = 273
Tfinal = 273/11.3
Tfinal = 24° C
Therefore, the final temperature aluminium-water system is 24° C
What does a low number on the pH scale say about a solution?
A. The solution is neutral.
B. The solution is a base.
C. The solution is changing.
D. The solution is an acid.
Answer:
d. the solution is a acid
Answer:D The solution is an acid
Explanation:The lower the pH of a substance the stronger the acidic level.
Soluitions and solubility
Answer:
solutions are homogeneous mixtures of two or more solutes in a solvent
solubility is the ability of a solute to dissolve in a solvent
Explanation:
hope this is helpful
Standardization of a Borax solution (Na2B4O7). You are given a 1.044 M solution of H2SO4. It takes 2.63 mL of this H2SO4 to reach the end point. Knowing it takes 1 H2SO4 to neutralize 2 Na2B4O7, what was the concentration of this Borax solution?
The question is incomplete, the complete question is:
Standardization of a Borax solution (Na2B4O7). A student titrates a 20.00 mL sample of an aqueous borax solution with 1.044 M H2SO4. It takes 2.63 mL of acid to reach the equivalence point. Knowing it takes 1 H2SO4 to neutralize 2 Na2B4O7, what was the concentration of this Borax solution?
Answer: The concentration of borax solution is 0.069 M.
Explanation:
To calculate the concentration of borax solution, the formula used is:
[tex]n_1C_1V_1=n_2C_2V_2[/tex] ....(1)
where,
[tex]n_1, C_1\text{ and }V_1[/tex] are the n-factor, concentration and volume of sulfuric acid
[tex]n_2,C_2\text{ and }V_2[/tex] are the n-factor, concentration and volume of borax solution.
We are given:
[tex]n_1=1\\C_1=1.044M\\V_1=2.63mL\\n_2=2\\C_2=?M\\V_2=20mL[/tex]
Putting values in equation 1, we get:
[tex]1\times 1.044\times 2.63=2\times C_2\times 20\\\\C_2=\frac{1\times 1.044\times 2.63}{2\times 20}\\\\C_2=0.069M[/tex]
Hence, the concentration of borax solution is 0.069 M.
Helppppp plz ASAP DON’T GUESS
Explanation:
A B C D isme koyi ans hain doond lo
What is the function of the rough
ER?
A. build proteins
B. modify and repackage proteins
C. contains enzymes
A. build proteins
Explanation:
The endoplasmic reticulum can either be smooth or rough, and in general its function is to produce proteins for the rest of the cell to function. The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins
set goals and objectives for a company
Explanation:
Objectives and goals serve as a foundation for successful organizations since they establish the business's objective and aid in the identification of required measures. Goals are broad assertions of what you want to achieve, whereas goals are the precise stages or steps you need to take to get there.
What exacerbates the heat waves?
Answer:
A heatwave occurs when a system of high atmospheric pressure moves into an area and lasts two or more days.
Explanation:
In such a high-pressure system, air from upper levels of our atmosphere is pulled toward the ground, where it becomes compressed and increases in temperature.
Jason combines the two intermediate steps shown. 2 equations. First: upper N subscript 2 (g) plus upper O subscript 2 (g) right arrow 2 upper N upper O (g). Second: 2 upper N upper O (g) plus upper O subscript 2 (g) right arrow 2 upper N upper O subscript 2 (g). Which best describes what Jason should do with the oxygen molecules?
Answer:
The molecules of oxygen should be placed as reactants in the equation.
Explanation:
1: N₂ + O₂ → 2NO
2: 2NO + O₂ → 2NO₂
complete reaction:
N₂ + 2O₂ → 2NO₂
In both intermediate equations' oxygen is used as reactant because the end product is the product of the combination of nitrogen and oxygen. So in the complete or overall reaction, oxygen should also be placed as reactant.We can not place oxygen at the side of products neither we can cancel it because, products can only be obtained at the end of the reaction but according to the equations' oxygen is not the end product of the reaction. But the addition into the reaction (Eq. 2) to make the new product.
Also, we can not cancel it because to cancel out molecules of oxygen should be present at the both sides with same amount in the stoichiometric equation.
Hence, in a balanced chemical equation, oxygen should be written as a reactant by using the correct number of moles.
32. Calculate the pH of a solution at 1.00 x 10- MIH") and identify the substance as an acid or base,
Answer:
[tex]{ \boxed{ \tt{formular : pH = - log[H {}^{ + } ]}}} \\ pH = - log(1.00 \times {10}^{-6} ) = 6: it's an acid\\ since \: we \: lack \: the \: exponent, \: this \: question \: is \: unsolvable \\ { \green{ \bf{take \: note}}} :{ \tt{pH \: below \: 7 \: that \: is \: { \red{acidic}}. \: \: pH \: greater \: than \: 7 \: is \: { \red {basic}}}}[/tex]
What is the predicted change in the boiling point of water when 2.10 g of
barium chloride (BaCl2) is dissolved in 5.50 kg of water?
The addition of any non-volatile solutes will elevate the boiling point of the solution. The change in boiling point of water by the addition of 2.10 of barium chloride is 0.0028 ° C. Hence, option A is correct.
What is boiling point?Boiling point of a substance is the temperature at which it changes from liquid to vapour where the two states are in equilibrium. Boiling point of a substance depends on the bond type, molecular mass and purity of it.
The change or elevation of boiling point of a solution can be determined from its molality m and elevation constant Kb and the Van't Hoff factor i as follows:
ΔT = i Kb m.
Molality of the solution is the no.of moles divided by the mass of solvent in kilogram. Given the mass of barium chloride is 2.10 g and its molar mass is 208.23 g . The no.of moles of solute is 2.10/208.23 g = 0.0100.
Molality of the solution can be calculated as follows:
Molality m = 0.0100 / 5.50 Kg
= 0.0018 mol/kg.
Now, the ΔT s calculated from these values. Provided Kb of water is 0.51 ° C /mol and i = 3.
ΔT = 0.0018 mol/kg × 0.51 × 3
= 0.0028 ° C.
Therefore, water will boil at 100.0028 ° C. Hence, option A is correct.
To find more about boiling point, refer the link below:
https://brainly.com/question/28203474
#SPJ1
Given that the acceleration due to gravity is 10N/Kg, calculate the weight of the
Mass (Show all you're working)
Answer:
Weight = 500 Newton
Explanation:
Given the following data;
Acceleration due to gravity = 10N/Kg
Weight can be defined as the force acting on a body or an object as a result of gravity.
Mathematically, the weight of an object is given by the formula;
[tex] Weight = mg [/tex]
Where;
m is the mass of the object.g is the acceleration due to gravity.Note: In order to calculate the weight of a mass, it's required that the mass of an object or body is given.
However, in this particular question it was omitted in error and as such i would assume a value.
Let mass, m = 50 kgSubstituting into the formula, we have;
[tex] Weight = 50 * 10 [/tex]
Weight = 500 Newton
