Answer:
6 protons 8 neutrons 5 electrons
Explanation:
protons are blue neutrons are red electrons are green
What is the density of a block of gold that occupies 1000 ml and has a mass of 3.5 kg? Show your work
Answer:
We are given:
mass of the block = 3500 grams
volume of the block = 1000 mL
Finding the density:
Density = mass of the object (in grams) / volume of the object (in mL)
Density = 3500 / 1000
Density = 3.5 g / mL
How many moles of precipitate will be formed when 100.0 mL of 0.200 M NaBr is reacted with excess Pb(NO₃)₂ in the following chemical reaction?
2 NaBr (aq) + Pb(NO₃)₂ (aq) → PbBr₂ (s) + 2 NaNO₃ (aq)
Answer : The number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.
Explanation : Given,
Concentration of NaBr = 0.200 M
Volume of solution = 100.0 mL = 0.1 L (1 L = 1000 mL)
First we have to calculate the moles of NaBr.
[tex]\text{Moles of NaBr}=\text{Concentration of NaBr}\times \text{Volume of solution in L}[/tex]
[tex]\text{Moles of NaBr}=0.200M\times 0.1L=0.02mol[/tex]
Now we have to calculate the moles of precipitate, [tex]PbBr_2[/tex] formed.
The balanced chemical reaction is:
[tex]2NaBr(aq)+Pb(NO_3)_2(aq)\rightarrow PbBr_2(s)+2NaNO_3(aq)[/tex]
From the balanced chemical reaction we conclude that:
As, 2 moles of NaBr react to give 1 mole of [tex]PbBr_2[/tex]
So, 0.02 moles of NaBr react to give [tex]\frac{0.02}{2}=0.01[/tex] mole of [tex]PbBr_2[/tex]
Therefore, the number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.
The number of mole of the precipitate (i.e PbBr₂) formed when 100 mL of 0.2 M NaBr react with excess Pb(NO₃)₂ is 0.01 mole
We'll begin by calculating the number of mole of NaBr in 100 mL of 0.2 M NaBr solution. This can be obtained as follow:Volume = 100 mL = 100 / 1000 = 0.1 L
Molarity of NaBr = 0.2 M
Mole of NaBr =?Mole = Molarity x Volume
Mole of NaBr = 0.2 × 0.1
Mole of NaBr = 0.02 mole Finally, we shall determine the number of mole of the precipitate (i.e PbBr₂) produced from the reaction. This can be obtained as follow:2NaBr(aq) + Pb(NO₃)₂(aq) → PbBr₂(s) + 2NaNO₃ (aq)
From the balanced equation above,
2 moles of NaBr reacted to produce 1 mole of PbBr₂.
Therefore,
0.02 mole of NaBr will react to produce = [tex]\frac{0.02}{2} \\\\[/tex] = 0.01 mole of PbBr₂.
Thus, the number of mole of the precipitate (i.e PbBr₂) produced from the reaction is 0.01 mole
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A student reacts 5.0 g of sodium with 10.0 g of chlorine and collect 5.24 g of sodium chloride. What is the percent yield of this combination reaction
Answer: The percent yield of this combination reaction is 41.3 %
Explanation : Given,
Mass of [tex]Na[/tex] = 5.0 g
Mass of [tex]Cl_2[/tex] = 10.0 g
Molar mass of [tex]Na[/tex] = 23 g/mol
Molar mass of [tex]Cl_2[/tex] = 71 g/mol
First we have to calculate the moles of [tex]Na[/tex] and [tex]Cl_2[/tex].
[tex]\text{Moles of }Na=\frac{\text{Given mass }Na}{\text{Molar mass }Na}[/tex]
[tex]\text{Moles of }Na=\frac{5.0g}{23g/mol}=0.217mol[/tex]
and,
[tex]\text{Moles of }Cl_2=\frac{\text{Given mass }Cl_2}{\text{Molar mass }Cl_2}[/tex]
[tex]\text{Moles of }Cl_2=\frac{10.0g}{71g/mol}=0.141mol[/tex]
Now we have to calculate the limiting and excess reagent.
The balanced chemical equation will be:
[tex]2Na+Cl_2\rightarrow 2NaCl[/tex]
From the balanced reaction we conclude that
As, 2 mole of [tex]Na[/tex] react with 1 mole of [tex]Cl_2[/tex]
So, 0.217 moles of [tex]Na[/tex] react with [tex]\frac{0.217}{2}=0.108[/tex] moles of [tex]Cl_2[/tex]
From this we conclude that, [tex]Cl_2[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]Na[/tex] is a limiting reagent and it limits the formation of product.
Now we have to calculate the moles of [tex]NaCl[/tex]
From the reaction, we conclude that
As, 2 mole of [tex]Na[/tex] react to give 2 mole of [tex]NaCl[/tex]
So, 0.217 mole of [tex]HCl[/tex] react to give 0.217 mole of [tex]NaCl[/tex]
Now we have to calculate the mass of [tex]NaCl[/tex]
[tex]\text{ Mass of }NaCl=\text{ Moles of }NaCl\times \text{ Molar mass of }NaCl[/tex]
Molar mass of [tex]NaCl[/tex] = 58.5 g/mole
[tex]\text{ Mass of }NaCl=(0.217moles)\times (58.5g/mole)=12.7g[/tex]
Now we have to calculate the percent yield of this reaction.
Percent yield = [tex]\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100[/tex]
Actual yield = 5.24 g
Theoretical yield = 12.7 g
Percent yield = [tex]\frac{5.24g}{12.7g}\times 100[/tex]
Percent yield = 41.3 %
Therefore, the percent yield of this combination reaction is 41.3 %
Determine the value of the equilibrium constant (report your answer to three significant figures) for the following reaction if an equilibrium mixture contains 0.010 mol of solid PbBr2, and is 0.0100 M in Pb2+ ions and 0.0250 M in Br1- ions. Use the notation 4.31e-5 to indicate a number such as 4.31 x 10-5.
Answer:
6.25e-6 is the value of the equilibrium constant
Explanation:
we have this equation
[tex]PbBr(s) ----- Pb^{2+}(aq) + 2Br(aq)[/tex]
When at a state of equilibrium,
we have the concentration of Pb^2+ to be 0.01
we have the concentration of Br^- to be 0.025
the equilibrium constant concentration of both pure solids and liquid s are said to be equal to 1
[PbBR2] = 1
such tht
Keq = [Pb^2+] x [Br-]^2
we already know the values of these from the above.
0.01x0.025^2
= 0.01 x 0.000625
= 0.00000625
= 6.25 x 10^-6
= 6.25e^-6
How many moles are in 141.16 grams of F?
Use two digits past the decimal for all values
Answer: 2681.81
Explanation:
How does temperature affect the copper (II) chloride equilibrium? Is the forward reaction (color changing from blue to green) endothermic or exothermic? Justify your choice with experimental evidence i.e color changes in the video for Part B.
Answer:
See explanation
Explanation:
A popular experiment that describes the effect of heat on the position of equilibrum is the change of colour when copper II chloride is heated.
As the solution is heated, it's colour changes from blue to green, this implies the the colour change (blue to green) is an endothermic process (equilibrum position shifts to the right with increase in temperature)
The equilibrum is represented by the equation;
[Cu(H2O)6]^2+(aq) + 4Cl^-(aq)<------>[CuCl4]^2-(aq) + 6H2O(l) ∆H=positive
The equilibrium mixture undergoing cooling or heating have colour changes. The temperature affects the colour of the products formed and the forward reaction is endothermic.
What are the equilibrium and the forward reactions?In the reaction copper (II) chloride or [tex]\rm CuCl_{4}[/tex] is the main species. The heat or the temperature affects the colour formation of copper (II) chloride as the equilibrium change affects the colouration of the product.
The heating of the solution affects the colour change from blue to the green of the reactant to products and the forward reaction shifts the equilibrium towards the right when the temperature is increased and is an endothermic reaction.
The reaction at the equilibrium can be shown as,
[tex]\rm [Cu(H_{2}O)_{6}]^{2+} (aq) + 4Cl^{-} (aq) \Leftrightarrow [CuCl_{4}]^{2-}(aq) + 6H_{2}O(l), \Delta H=positive[/tex]
Therefore, temperature changes the colouration and the forward reaction is an endothermic reaction.
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What is the process of cell eating called
Answer:
Phagocytosis
Explanation:
When 435 J of heat is added to 3.4 g of olive oil that's at 21 Deg C, it's
temperature increases to 85 Deg C. Calculate the specific heat of Olive oil? Show work
Answer:
k Nishant
Explanation:
i don't know sorry but u can search in google
Determine the molar mass of CaO
A chemist prepares a solution of silver(II) oxide by measuring out 0.0013 of silver(II) oxide into a 100 mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's silver(II) oxide solution. Be sure your answer has the correct number of significant digits.
Answer:
1.3x10⁻⁸ mol/L
Explanation:
0.0013μmol, Calculate concentration in mol/L
To obtain concentration in mol/L we need to convert the μmoles to moles and mL to liters:
Moles silver(II) oxide:
0.0013μmol × (1mol / 1x10⁶μmol) = 1.3x10⁻⁹ moles
Liters solution:
100mL * (1L / 1000mL) = 0.1L
That means concentration in mol/L is:
1.3x10⁻⁹ moles / 0.1L =
1.3x10⁻⁸ mol/LPlease help!!
This is a big part of my grade -----
Will make you brainliest******
Explanation:
U need to draw the graph first and make a line at 17 pennies, where the line of 17 pennies and your graph meet is the mass of it(at y axis)
HELP PLEASE, IM ON A TIMER ⏱
Which describes an attribute of nonrenewable resources?
A.) exist in fixed amounts
B.) are unlimited
C.) can often be replaced in a short time
D.) are replaced faster than they are used
Answer:
A. exist in fixed amounts or available in limited supplies
Explanation:
Answer:
A
Explanation:
What was the atomic theory about?
A. The properties of the nucleus
B. The existence of isotopes
C. The structure of the atom
D. The existence of electrons
Answer:
The structure of the atom
How many elements are in calcium dihydrogren phosphate
Y-Chart
Explain how an invasive species can influence each aspect of an ecosystem.
Answer:
Invasive species are an organism that causes ecological or economic harm in a new environment where it's not native.
Explanation:
An invasive species can harm both the natural resources in the ecosystem as well it threaten the human use of these resources and invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and etc.
Invasive species is capable of causing extinctions to native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. This can also result a huge economic impacts and fundamental disruptions of coastal and the great lakes of the ecosystems.
I hope it helps you.
__________ 5. Chemical equilibrium is the result of A. all of the reactants being converted into products. B. stoppage of further reaction. C. formation of products equal in mass to the mass of the reactants. D. opposing reactions attaining equal rates. E. a loss of pressure in the system.
Answer:
The correct option is C
Explanation:
Chemical equilibrium is a state in which there is no net change in the amount of reactant and products formed over time. This reaction is a reversible reaction, hence the reaction can keep proceeding in either direction until the products formed are equal in mass to that of the reactants or the products been reversed back to the reactants until both sides (product and reactant) achieve equal mass.
convert 575.1 mmHg to atm
Answer:
= .7567105263
Explanation:
1 atm = 760 mmHg
575.1 mmHg (1 atm/760mmHg) = .7567105263 atm
How do the test variables (independent variables) and outcome variables (dependent variables) in an experiment compare? A. The test variables (independent variables) and outcome variables (dependent variables) are the same things. B. The test variable (independent variable) controls the outcome variable (dependent variable). C. The test variable (independent variable) and outcome variable (dependent variable) have no affect on each other. D. The outcome variable (dependent variable) controls the test variable (independent variable).
Answer:
I'm on the exact same queston
Answer:
The test variable (independent variable) controls the outcome variable (dependent variable)
Explanation:
its right on study island
An ideal gaseous reaction (which is a hypothetical gaseous reaction that conforms to the laws governing gas behavior) occurs at a constant pressure of 35.0 atm and releases 74.6 kJ of heat. Before the reaction, the volume of the system was 8.20 L . After the reaction, the volume of the system was 2.80 L . Calculate the total internal energy change, ΔE, in kilojoules.
Answer:
ΔU = −55.45 kJ
Explanation:
From first law of thermodynamics in chemistry, we have;
ΔU = Q + W
where;
ΔU is change in internal energy
Q is the net heat transfer
W is the net work done
We are given;
Q = 74.6 kJ
But Q will be negative since heat is released
Thus;
ΔU = -74.6 kJ + W
We are given;
Constant pressure; P = 35 atm = 35 × 101325 = 3546375 N/m²
Volume before reaction; Vi = 8.2 L = 0.0082 m³
Volume after reaction; V_f = 2.8 L = 0.0028 m³
Now,
W = -P(V_f - V_i)
W = - 3546375(0.0028 - 0.0082)
W = 19.15 KJ
Thus;
ΔU = Q + W
ΔU = -74.6 kJ + 19.15 KJ =
ΔU = −55.45 kJ
What does a dissolved salt look like?
Answer:(trick question) once the salt has dissolve in the water it is no longer visible
Thank you! have an amazing day.
PLEASE HELP AND FAST!!!
The amount of force that is exerted on a balloon by the gas inside the balloon is.
O A) temperature
OB) prlessure
O C) volume
O D) heat
Answer:
pressure
Explanation:
pressure is the amount of force exerted on an area. when you blow up the balloon you're filling it with gas particles. the gas particles move freely within the balloon and may collide with one another exerting pressure on the inside of the balloon.
The pressure of the gas is the amount of force that is exerted on a balloon by the gas inside the balloon. Therefore, option B is correct.
What is pressure?Pressure can be described as the force applied perpendicular to the surface of a body per unit area. Pressure can be defined as a standard mechanical quantity and is derived from a unit of force divided by a unit of area.
The SI unit of measurement of pressure, the pascal (Pa) or Newton per square meter (N/m²). Pressure can be defined as the amount of force exerted perpendicular to the surface per unit area.
Mathematically, the pressure exerted by force can be calculated as:
[tex]{\displaystyle p={\frac {F}{A}}}[/tex]
where, p is the pressure, F is the magnitude of the normal force, and A is the area of the surface.
Therefore, the amount of force that is exerted on the balloon by the gas inside the balloon is equal to pressure.
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Please help me!!!:)))
Answer:
blocks 1 and 2 the rhdh huff hgfhh5
How many atoms are in 10 g of He
Answer:
6.7
⋅
10
23
atoms of H
Explanation:
Which number represetns a coefficient?
2
3
4
7
Cementation is part of the process of
A. igneous intrusion
B. lithification
C. igneous extrusion
D. metamorphism
SUBMIT
Answer:
The correct answer is b.
Explanation:
hope this helps u
Answer:
Bryna is correct it is B
Explanation:
When a helium balloon rises in the air, it expands. If the volume of the balloon doubles, what happens to the density of the helium inside it?
a.The density decreases by half
b.The density doubles
c.The density triples
d.The density stays the same
1. Marisa determined the melting point of a substance to be 24.5C. Find the percent error of her measurement if the actual melting point is 31.2C.
Answer:
[tex]\%\ Error = 21.5\%[/tex]
Explanation:
Given
[tex]Measured = 24.5[/tex]
[tex]Actual = 31.2[/tex]
Required
Determine the percentage error
First, we need to determine the difference in the measurement
[tex]Difference = |Actual - Measured|[/tex]
[tex]Difference = |31.2 - 24.5|[/tex]
[tex]Difference = |6.7|[/tex]
[tex]Difference = 6.7[/tex]
The percentage error is calculated as thus:
[tex]\%\ Error = \frac{Difference * 100\%}{Actual}[/tex]
[tex]\%\ Error = \frac{6.7 * 100\%}{31.2}[/tex]
[tex]\%\ Error = \frac{670\%}{31.2}[/tex]
[tex]\%\ Error = 21.4743589744\%[/tex]
[tex]\%\ Error = 21.5\%[/tex] approximated
True or False: All cells have different basic chemical composition. *
True
False
How is matter divided?