8.
A chain bracelet is found. It looks as though it might be made of either gold or of
copper. When the bracelet is submerged in a graduated cylinder containing water, the
volume of the water rises from 9.2 cm to 11.7 cm3. The bracelet has a mass of 45 g. Is
the bracelet made of gold or copper? (Note: The density of gold is 19.3 g/cm and the
density of copper is 8.92 g/cmº.)
Answer:
The bracelet is made of gold.
Explanation:
The bracelet displaces the water by [tex]11.7cm^3-9.2cm^3 = 2.5cm^3[/tex] and thus has a volume of [tex]2.5cm^3[/tex]. If the bracelet has a mass of 45g, we know that the density of the bracelet is then [tex]\frac{45g}{2.5cm^3}[/tex], which can be simplified to [tex]18\frac{g}{cm^3}[/tex]. This is closer to the density of gold, so it can be assumed that the bracelet is made of gold.
Define the following terms
a. crystallization
b. radical
c. mixture
a) Crystallization :- Crystallization is a chemical process in which the solid-liquid separation technique occurs. This process causes mass transfer of a solute from the liquid solution to a pure solid crystalline phase.
b) Radical :- A radical is an atom of an element or a group of atoms of different elements that behaves as a single unit with a positive or negative charge on it.
c) Mixture :- A mixture is a combination of two or more substances (elements or compounds) which is not done chemically.
Explanation:
Hope it helps you!!Answer:
(a) Crystallization is a process which helps to separate a pure solid from a solution in its crystal form. This is the in use to purify solid. For an example the salt we get from seawater can have many impurities in it. Hence, the process of crystallization is in use to remove these impurities.
(b) A radical is an atom of an element or a group of atoms of different elements that behaves as a single unit with a positive or negative charge on it.
(c) Mixtures are constituted by more than 1 kind of pure form known as substance. There are 2 types of mixture:-
(i) homogeneous
A mixture in which the constituents are uniformly distributed throughout without any clear boundary of separation
(ii) Heterogeneous
A mixture in which constituents don't have uniform composition and has a visible boundary of separation.
Explanation:
Abuse of time and temperature can occur in each of the following ways except: The items are not cooked to the proper internal temperature The items are cooked or reheated improperly The items are held at the wrong temperature The items are held in the freezer for too long
Holding items in the freezer for too long is not an example of abuse of time and temperature.
What is abuse of time and temperature?
Abuse of time and temperature has to do with a situation in which time is used in an improper way or food is not held at the correct temperature ultimately leading to food poisoning.
Holding items in the freezer for too long is not an example of abuse of time and temperature.
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In a constant-pressure calorimeter, the temperature of 60. 0 g of water increases by 4. 50 °C.
What amount of heat is transferred to the water? (Specific heat capacity of water = 4. 2 J/goC)
Answer:
1130 j
Explanation:
4.2 j/g-C * 60 g * 4.5 C =
In a catalyzed reaction a reactant is often called a:.
Answer:
The reactant in an enzyme-catalyzed reaction is called a substrate.
Explanation:
What is the freezing point of a solution in which 2.50 grams of sodium chloride are added to 230.0 ml of water
The freezing point of a solution in which 2.5 grams of NaCl is added t0 230 ml of water is : - 0.69°C
Determine the freezing point of the solution
First step : Calculate the molality of NaCl
molality = ( 2.5 grams / 58.44 g/mol ) / ( 230 * 10⁻³ kg/ml )
= 0.186 mol/kg
Next step : Calculate freezing point depression temperature
T = 2 * 0.186 * kf
where : kf = 1.86°c.kg/mole
Hence; T = 2 * 0.186 * 1.86 = 0.69°C
Freezing point of the solution
Freezing temperature of solvent - freezing point depression temperature
0°C - 0.69°C = - 0.69°C
Hence the Freezing temperature of the solution is - 0.69°C
Learn more about The freezing point of a solution in which 2.5 grams of NaCl is added t0 230 ml of water is : - 0.69°C
How much volume of butanol should be combined with 30.0 mL ethanol to make a 5.88% volume percent solution of ethanol in butanol
Percentage volume is the ratio of the mass of solute to the volume of the solution. The 510 ml volume of butanol should be combined with 30.0 mL ethanol.
What is volume percent?Volume percent is the percentage ratio of the volume of the solute to the volume of solution multiplied by 100. It is given as,
[tex]\rm Percent \; volume = \rm \dfrac{ \text{volume of solute}}{\text{volume of solution}}\times 100 \%[/tex]
Given,
Percent volume = 5.88%
Volume of solute = 30.0 mL
Substituting values in the equation above:
[tex]\begin{aligned} \rm Percent \; volume &= \rm \dfrac{ \text{volume of solute}}{\text{volume of solution}}\times 100 \%\\\\5.88 &=\rm \dfrac{30}{V} \times 100\%\\\\&= 510.20\end{aligned}[/tex]
Therefore, 510 ml is the volume of butanol that should be added to the solution.
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The value of the equilibrium constant, Kc, for a reaction will be __________. Select the correct answer below: independent of temperature independent of initial concentrations an exact number will always move the reaction from left to right
Answer:
Independent of initial concentrations
Explanation:
Initial concentrations do not affect equilibrium constant because equilibrium constant is found from equilibrium concentrations.
How many moles of MgO are produced when 7. 2 moles of O2 react with excess Mg
[tex] \frac{no {}^{2} }{1} = \frac{nmgo}{2} [/tex]
[tex]nmgo = no {}^{2} \times 2 = 7.2 \times 2 = 14.4[/tex]
Note that n stands for the number of moles.
is a Chemical change and a chemical reaction the same?
Answer: Heyo Kenji Here! Here's your answer- A chemical change is also called a chemical reaction. A chemical reaction is a process that occurs when one or more substances are changed into one or more new substances.
Explanation: Hope this helps!
Have a nice day!
- Kenji ^^
What is the alveolar ventilation rate of a person that has a tidal volume of 450 ml, a dead space volume of 125 ml, and a is breathing 15 breaths/min
Answer:
Total minute ventilation is comprised of dead space plus alveolar ventilation. Minute ventilation is respiratory frequency (14 breaths per minute) multiplied by tidal volume (450 mL/breath) = 6300 mL/min.
Explanation:
hope this helps you!
4. Magnesium and oxygen undergo a chemical reaction to
produce magnesium oxide.
2Mg + O2 + 2MgO
If 24.4 grams of magnesium react with oxygen gas to produce
40.5 grams of magnesium oxide, what is the mass in grams of
the oxygen gas in the chemical change?
Answer:
About 16.1 grams of oxygen gas.
Explanation:
The reaction between magnesium and oxygen can be described by the equation:
[tex]\displaystyle 2\text{Mg} + \text{O$_2$} \longrightarrow 2\text{MgO}[/tex]
24.4 grams of Mg reacted with O₂ to produce 40.5 grams of MgO. We want to determine the mass of O₂ in the chemical change.
Compute using stoichiometry. From the equation, we know that two moles of MgO is produced from every one mole of O₂. Therefore, we can:
Convert grams of MgO to moles of MgO. Moles of MgO to moles of O₂And moles of O₂ to grams of O₂.The molecular weights of MgO and O₂ are 40.31 g/mol and 32.00 g/mol, respectively.
Dimensional analysis:
[tex]\displaystyle 40.5\text{ g MgO} \cdot \frac{1\text{ mol MgO}}{40.31\text{ g MgO}} \cdot \frac{1\text{ mol O$_2$}}{2\text{ mol MgO}} \cdot \frac{32.00\text{ g O$_2$}}{1\text{ mol O$_2$}} = 16.1\text{ g O$_2$}[/tex]
In conclusion, about 16.1 grams of oxygen gas was reacted.
You will obtain the same result if you compute with the 24.4 grams of Mg instead:
[tex]\displaystyle 24.4\text{ g Mg}\cdot \frac{1\text{ mol Mg}}{24.31\text{ g Mg}} \cdot \frac{1\text{ mol O$_2$}}{1\text{ mol Mg}} \cdot \frac{32.00\text{ g O$_2$}}{1\text{ mol O$_2$}} = 16.1\text{ g O$_2$}[/tex]
A 25.00 mL sample of a hydrochloric acid solution was titrated to completion with 34.55 mL of 0.1020 M sodium hydroxide. What was the concentration of the hydrochloric acid
The concentration of hydrochloric acid with a volume of 25mL titrated with 34.55 mL of 0.1020 M sodium hydroxide is 0.141M.
How to calculate concentration?The concentration of an acid in a titration procedure can be calculated using the following expression:
CaVa = CbVb
Where;
Ca = concentration of acidCb = concentration of baseVa = volume of acidVb = volume of baseCa = ?Cb = 0.102MVa = 25mLVb = 34.55mLCa × 25 = 0.102 × 34.55
25Ca = 3.52
Ca = 0.141M
Therefore, the concentration of hydrochloric acid with a volume of 25mL titrated with 34.55 mL of 0.1020 M sodium hydroxide is 0.141M.
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. What are the benefits and consequences of using ethanol for fuel? Try to name a few of each.
Answer:
Advantages of Ethanol Fuel
Ethanol Fuel is Cost-effective Compared to Other Biofuels. ...
Ecologically Effective. ...
Helps Reduce Global warming. ...
Easily Accessible. ...
Minimizes Dependence on Fossil Fuels. ...
Contributes to Creation of Employment to the Country. ...
Opens up Untapped Agricultural Sector. ...
Ethanol Fuel is a Source of Hydrogen.
List of the Disadvantages of Ethanol
It isn't as effective a fuel as traditional gasoline. ...
It is a corrosive fuel. ...
It requires a lot of cropland space. ...
It is costly. ...
Its use has resulted in a net emissions increase. ...
It has altered food production principles. ...
It is reliant on the quality of the growing season.
Which following is an opinion about friction
Answer:
please give a photo of it
HELP ASAP SCIENCE GIVING BRAINLIST FOR CORRECT
Answer:
Jellyfish :)
Have an amazing day!!
Please rate and mark brainliest!!
A. Write the name of the alkane next to the drawing of the molecule. (2 points)
The names of the alkanes are all shown below;
3-methyl heptane2-methyl pentane2-methyl heptane2-methyl hexane 3-methyl hexaneWhat is an alkane?An alkane is a hydrocarbon that contains only hydrogen and carbon in which all the carbon to carbon bonds are saturated.
The names of the alkanes are all shown below;
3-methyl heptane2-methyl pentane2-methyl heptane2-methyl hexane 3-methyl hexaneLearn more about alkanes:https://brainly.com/question/24036551
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Which of the following can be said in the crystallization of liquid salt.
A.
Answer:
Correct option is D)
Explanation:
Crystallization is the process that is used to separate a pure solid in the form of its crystals from a solution.
Copper sulphate, salt, and potash alum can be purified by this method. In this process, the solution of the substance is heated and then cooled to form crystals.
Sodium and magnesium are used to displace titanium from
titanium chloride. What does this tell you about titanium?
A gas a temperature of 269.5K. What is the temperature in C°
Answer:
269.5k is equivalent to -3.65 c
Explanation:
1 Kelvin = 1 - 273.15 = -272.15 Celsius
269.5 Kelvin = 269.5 - 273.15 = -3.65 Celsius
hope it helped :)
269.5 K
to find:269.5 K in C°
solution:formula= 0K − 273.15 = -273.1°C
= -3.65 °C.
What two factors must be equal when a chemical reaction reaches equilibrium
Answer:
The correct answer is option 3. Equilibrium is achieved in a chemical reaction when the rate of the forward reaction is the same for the rate of the backward reaction and when the reaction has stopped.
Explanation:
Hydrochloric acid (HCI) and acetic acid (HC, H2O2) are both acids.
HCl completely dissociates in water, while HC2H2O2 does not.
Which statement best describes these two acids?
O HCl is a strong acid, HC2H2O2 is a weak acid.
O HCl is a weak acid, HC2H3O2 is a weak acid.
O HCl is a strong acid, HC2H2O2 is a strong acid.
O HCl is a weak acid, HC2H2O2 is a strong acid.
Answer:
I think that A or C is the correct answer
Answer:
HCl is a strong acid, HC2H2O2 is a weak acid.
Explanation:
strong acid: completely dissociates in water
weak acid: partially dissociates in water
b) Do all waves require a medium? Explain. (2 points)
Explanation:
Not all waves actually require a physical medium through which to travel. This fact allows us to put all waves into two broad categories:
Mechanical Wave - A wave that requires a physical medium through which to travel. Example - sound waves. Sound waves can not travel through a vacuum (empty space).
Electromagnetic Waves - Do not require a physical medium through which to travel. Electromagnetic waves can travel through a vacuum. Examples: Radio waves, visible light, x-rays, etc.
What is the MAXIMUM amount of the substance that will dissolve in 100 cm3 of water at 30OC?
A. 19 g
B. 30 g
C. 57 g
D. 125 g
Answer:
A 19g
Explanation:
Urgent!!!
Type the correct answer in the box. Express your answer to three significant figures.
The half-life of carbon-14 is 5,730 years. Dating organic material by looking for C-14 can’t be accurately done after 50,000 years.
Suppose a fossilized tree branch originally contained 4.30 grams of C-14. How much C-14 would be left after 50,000 years?
Use the formula N = N0(1/2)^t/T .
A tree branch that originally had 4.3 grams of carbon-14 will have _____ grams after 50,000 years.
Answer:
0.0102 g
Explanation:
A common formula for determining the amount of sample remaining in terms of its half-life is
where
t = 50 000 yr
Calculate n
n = 50 000/5730
n = 8.726
===============
N₀ = 4.30 g Calculate N
N = 4.30 × 2.36 × 10⁻³
N₀ = 0.0102 g
Explanation:
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what is the sun and is it enegery
An object that has potential energy may have this energy because of its
a acceleration
b location
c momentum
d speed
Answer:
i have no idea. let's say location because it has to be somewhere.
Explanation:
I
An ice cube is placed on a kitchen counter. which best describes heat flow in this situation? heat flows from the ice to the counter, causing the molecules in the counter to move more quickly. heat flows from the ice to the counter, causing the molecules in the counter to move more slowly. heat flows from the counter to the ice, causing the molecules in the counter to move more quickly. heat flows from the counter to the ice, causing the molecules in the counter to move more slowly.
An ice cube is placed on a kitchen counter then heat flows from the counter to the ice, causing the molecules in the counter to move more slowly.
What is heat flow?Heat flow is a process in which heat is transfered from hot body to the cold body.
So, when we place an ice cube to the counter of the kitchen and here ice is a colder body and counter is a warmer body so transfer of heat takes place from counter to the ice cube. As a result of which movement of particles of counter gets slow and of ice increases.
Hence in the given situation heat flows from the counter to the ice, causing the molecules in the counter to move more slowly.
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Answer:
D
Explanation:
Edge 2022
Classify each of the coordination compounds according to the coordination number.
Coordination number has to do with the number of ligands that is attched to the central metal atom/ion.
What is coordination number?The term coordination number has to do with the number of ligands that is attched to the central metal atom/ion. The coordination sphere contains this central metal along with associated ligands.
The question is incomplete. However, if I have something like, K3[Cr(H2O)6], the coordination number of the complex is six.
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what does the sides of a container do with a gas
Answer:
If a gas is heated up, its particles move around more quickly. They hit the walls of their container harder and more often.
Explanation: