Answer:
56.6g
Explanation:
Given that :
Mass of water, m1= 300.0 g
Temperature of water, T1= 22°C
Specific heat capacity of water, C= 4.184 J/g°C
Mass of polystyrene, m2=?
Temperature of polystyrene = 94.9
Specific heat capacity of polystyrene, c2= 1.88 J/g°C
Final temperature = 27.7 oC
Heat lost by polystyrene = Heat gained by water
mc(dT) = mc(dT)
m2 * 1.88 * (94.9 - 27.7) = 300 * 4.184 * (27.7 - 22)
m2 * 1.88*67.2 = 300*4.184*5.7
126.336 * m2 = 7154.64
m2 = 7154.64 / 126.336
m2 = 56.631838
Hence, mass of polystyrene = 56.6g
A normal adult jawbone contains 200 mg of Carbon-14 in a living person. If scientists found a jawbone that only had 50mg of Carbon-14, how old is the bone? (The half-life of C-14 is 5730 years).
Carbon-14 is a radioisotope of carbon that decays following first-order kinetics. There are four values of interest in this problem: the "normal" (or original) amount of carbon-14 for a jawbone ([tex]\mathrm{N_0}[/tex]), the actual amount of carbon-14 in a jawbone ([tex]\mathrm{N}[/tex]), the half-life of carbon-14 ([tex]\mathrm{t_{1/2}}[/tex]), and the actual time elapsed ([tex]\mathrm{t}[/tex]) from the original time. There is an equation that ties all these values in together,
[tex]N= N_0 e^{-kt}[/tex]
where k is the rate constant, which, for first-order decay, is related to the half-life by
[tex]k = \dfrac{\ln 2}{ t_{1/2} }.[/tex]
What you want to find here is the time elapsed (t). So, you can substitute the latter equation for k into the k in the former equation to get
[tex]N= N_0 e^{\frac{-\ln 2 \;t}{t_{1/2}}.[/tex]
Rearranging to solve for t, the equation becomes
[tex]t = \left(\dfrac{\ln \dfrac{N_0}{N}}{\ln 2} \right) t_{1/2}.[/tex]
You are given all three of the values necessary to solve for t: The normal amount of carbon-14 is 200 mg; the actual amount of carbon-14 in the sample is 50 mg; and the half-life of carbon-14 is 5730 years. Plugging them into the above equation, we get
[tex]t = \left(\dfrac{\ln \dfrac{200 \text{ mg}}{50 \text{ mg}}}{\ln 2} \right) \left(5730 \text{ years} \right) = 11460 \text{ years}.[/tex]
So the jawbone found is 11460 years old (or 11000 if accounting for sig figs).
mhanifa, can you answer this question pls?
Solve for x.
1. 5(2x +15) = 55
2. 9(6x +4) = 166
3. 3(8x +20) = 356
Answer:
1. x=-2
2. x=65/27
3. x=37/3
Explanation:
Isolate x
1. Divide by 5: 2x+15=11
2x=11-15
x=-2
2. Distribute: 54x+36=166
54x=166-36
x=130/54
Simplify by dividing by 2: x=65/27
3. Distribute: 24x+60=356
24x=356-60
x=296/24
Simplify by dividing by 8: x=37/3
How much of NaCl is in 1.14 L of 0.400 M
NaCl?
Answer:
44 g NaCI
Explanation:
The problem provides you with the molarity and volume of the target solution, so your first step here will be to use this information to figure out how many moles of sodium chloride.
Which of the following statements best goes with the Law of Conservation of Energy?
all energy conversions are 100% efficient
O all energy from the sun is transferred to organisms directly by the 10% rule
O all of the sun's energy is either transformed into kinetic energy, and eventually heat energy
O all matter cannot be created or destroyed
Answer:
all letter cannot be created or destroyed just transformed
Question 4 (4 points)
(01.03 MC)
An energy transformation flow diagram is shown.
X-
ELECTRICAL
ENERGY
What type of energy does X most likely represent? (4 points)
O a
X = gravitational energy
Oь
X = mechanical energy
Ос
= thermal energy
Od
X = radiant energy
Answer:
I think radiant I’m not sure
Explanation:
Put these elements in order of decreasing electronegativity, with the highest electronegative element as number 1.
a. tin (Sn, Group 14, Period 5)
b. rubidium (Rb, Group 1, Period 5)
c. bromine (Br, Group 17, Period 4)
d. lithium (Li, Group 1, Period 2)
e. cadmium (Cd, Group 12, Period 5)
Answer:the answer is a c and e
Explanation:
Household hydrogen peroxide is an aqueous solution of hydrogen peroxide (H2O2), and its concentration is often measured as a percent by weight. Most drug stores sell 3% solution, which means there are 3.0 g of H2O2 per every 100 g total of solution (H2O2 H2O). For the kinetics experiment, 15 mL of 3% (w/w) hydrogen peroxide solution was poured into a measuring cup with 120 mL of water. 5 mL of 1M sodium carbonate solution (Na2CO3) was also added to the mixture. What is the molar concentration (molarity) of hydrogen peroxide (in mol/L) of the final solution
Answer:
0.093 M
Explanation:
First, we assume that the density of household hydrogen peroxide is 1 g/mL. We also assume that there's no reaction between hydrogen peroxide and sodium carbonate, if there were, in the end all hydrogen peroxide would be consumed.
Now we calculate how many grams of H₂O₂ were added, using the given volume, concentration and density:
15 mL * [tex]\frac{1gSolution}{1mL}*\frac{3gH_2O_2}{100gSolution}[/tex] = 0.45 g H₂O₂We convert grams to moles:
0.45 g H₂O₂ ÷ 34 g/mol = 0.013 mol H₂O₂
Now we divide the number of moles by the final volume, to calculate the molarity of H₂O₂:
Final Volume = 15 mL + 120 mL + 5 mL = 140 mL140 mL / 1000 = 0.140 LMolarity = 0.013 mol H₂O₂ / 0.140 L = 0.093 MBased on the given concentration of the original hydrogen peroxide solution, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.
What is the concentration of the hydrogen peroxide solution?Assuming that the density of household hydrogen peroxide is 1 g/mL and that no reaction occurs between hydrogen peroxide and sodium carbonate.
The mass in grams of H₂O₂ added is first determined using the given volume, concentration and density:
mass = volume * density * concentrationmass = 15 mL * 1 g/mL * 3g/100g = 0.45 g H₂O₂
Moles of H₂O₂ is determined as follows:
moles = mass /molar massmolar mass of H₂O₂ = 34 g/mol
moles of H₂O₂ = 0.45 g H₂O₂ / 34 g/mol
moles of H₂O₂ = 0.013 mol H₂O₂
molarity of H₂O₂ is then calculated as follows:
molarity = moles/volume in Lfinal volume = 15 mL + 120 mL + 5 mL = 140 mL
final volume = 140 mL / 1000 = 0.140 L
molarity = 0.013 mol H₂O₂ / 0.140 L
molarity of H₂O₂ = 0.093 M
Therefore, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.
Learn more about molarity at: https://brainly.com/question/17138838
Help please !!!!!!! 10 points for this
In humans, normal color perception (N) dominates the expression of color blindness (n), and both of these genes are carried on the X chromosome (XN or Xn). A woman with normal color vision has a color-blind father. Her husband is also color-blind.
a. What is the genotype of the colorblind man? ____
b. What is the genotype of the woman? ______
c. What is the probability of her daughter to be colorblind? __________%
d. What is the probability of her sons to be colorblind? _________%
WHO CAN HELP ME
Answer:
a: Nn or XN
b: Nn or Xn
c: 75%
d: 50%
Explanation:
Specific Gravity is also known as ______________
State the postulate of Bohr theory
Answer:
Bohr's model of the hydrogen atom is based on three postulates:
1) An electron moves around the nucleus in a circular orbit,
2) An electron's angular momentum in the orbit is quantised,
3) The change in an electron's energy as it makes a quantum jump from one orbit to another is always accompanied by the emission or absorption of a photon. Bohr's model is semi-classical because it combines the classical concept of electron orbit (postulate 1) with the new concept of quantisation ( postulates 2 and ).
can you help me with my science
anyone wanna do my chem test for 500 points? my insta is niqsariot_1 hmu if your interested and for everyone else FREE 100 POINTS
Answer:
I would be if I do it your no learning anything but I would but I don't have insta yet
Explanation:
sorry
Answer:
k
Explanation:
An element X has a triiodide with the empirical formula XI3 and a trichloride with the empirical formula XCl3. The triiodide is converted to the trichloride according to the equation XI3 Cl2XCl3 I2 If the complete conversion of 1.196 g of XI3 results in the formation of 0.436 g of XCl3, what is the atomic mass of the element X
Answer:
51.03g/mol is the molar mass of X
Explanation:
Based on the reaction:
2XI₃ + 3Cl₂X → 2XCl₃ + 3I₂
Where 2 moles of XI₃ reacts to produce 2 moles of XCl₃ -The ratio of reaction is 1:1-
To solve this question we must find the mass of X per mole (This is the atomic mass of X).
As the moles of both compounds are the same:
1.196g / 0.436g = Molar mass XI₃ / molar mass XCl₃ (1)
Also:
Molar mass XI₃ = Molar mass X + 380.71g/mol
Molar mass XCl₃ = Molar mass X + 106.36g/mol
Replacing in (1):
2.7431 = (Molar mass X + 380.71g/mol) / (Molar mass X + 106.36g/mol)
2.7431 Molar mass X + 291.76g/mol = Molar mass X + 380.71g/mol
1.7431 Molar mass X = 88.95g/mol
Molar mass X = 51.03g/mol
51.03g/mol is the molar mass of XIf someone is building a scale model of our solar system which characteristic would be the most difficult to build into the model?
1#The relative sizes of the objects
2#The colors of the objects
3#The distances between objects
4#The composition of the objects
Answer:
The composition of the objects because not all the planets have been explored
What is the molecular formula for a compound that is 44.87% potassium, 36.7%
oxygen, 18.0% sulfur and a molecular mass of 696g.
Answer:
Molecular formula: S4K8O16 empirical formula: SK2O4
Explanation:
First we find the moles of each by first finding grams (using the percent) and then using stoichiometry to convert into moles:
Sulfur: 696 *.18 = 125.28grams S* [tex]\frac{1 mole S}{32.065 g S} = 3.907 moles S[/tex]
Potassium: 696 *.4487 = 312.2952 *[tex]\frac{1 mole K}{39.08 g K}[/tex]= 7.99117 mole K
Oxygen: 696 * .367 = 255.432 * [tex]\frac{1 mol O}{16g O}[/tex] = 15.9654 mole O
Then we divide each value by the atom with the smallest number of moles to find the mole ratio:
3.907/3.907= 1
7.99117 mole K/ 3.907= 2.043
15.9654 mole O/ 3.907= 4.08
The empirical formula is SK2O4
To find the molecular formula, we divide the mass given (696) by the mass of the empirical formula (174.22) to get 4. We then divide each atom by 4.
Molecular formula: S4K8O16
The PH of a solution of Hcl is 2.find out the amount of acid present in a litre of the solution
Answer:
The solution is 10^-2 or 0.01M in HCl.
Explanation:
meaning of pH is "power of hydrogen".
what is the molar concentration of a HCl solution with pH=2?
Let say pH=2
[H+]=10^-2M
HCL is a strong acid that dissociates completely:
[H+]=[HCL]
Therefore solution is 10^-2 or 0.01M in HCL.
PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP
DUE IN 5 MINUTES CHEMISTRY DIMENSIONAL ANALYSIS
In 2009, Usain Bolt ran 100 meters in 9.58 seconds. What is this speed in km/hr? (!! DIMENSIONAL ANALYSIS!! NOT A REGULAR PROBLEM)
Which processes are part of the fast carbon cycle?
A) Transpiration and fossil fuel formation
B) Transportation and photosynthesis
C) Cellular respiration and photosynthesis
D) Deforestation and fossil fuel formation
Answer:
B) Transportation and photosynthesis
C) Cellular respiration and photosynthesis
Order the sequence of steps that occur when you add heat to a chemical reaction. Place these steps in a logical order keeping in mind how adding temperature affects the rate of reaction.
The reaction rate of the experiment is recorded and found to have occurred at a faster rate than it did without the addition of heat.
Temperature increases due to the higher ketic energy of particles.
Two chemicals are mixed together and slowly some bubbles appeanr
Heat is added to the experiment with a Bunsen burner.
More collisions of particles occurs due to the increased kinetic energy.
Answer:
C,A,B,D
Explanation:
That's the correct order, hope this helps
PLEASE HELP!!
15POINTS!!! And brainliest
Answer: a. 3.36 L
b. 33.2 g
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
Standard condition of temperature (STP) is 273 K and atmospheric pressure is 1 atm respectively.
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
[tex]\text{Number of moles of} Fe_2O_3=\frac{16.0g}{159.69g/mol}=0.1mole[/tex]
[tex]3O_2(g)+4Fe(s)\rightarrow 2Fe_2O_3(s)[/tex]
a. 2 moles of [tex]Fe_2O_3[/tex] are produced by = [tex]3\times 22.4L=67.2L[/tex] of [tex]O_2[/tex]
Thus 0.1 moles of [tex]Fe_2O_3[tex] are produced by =[tex]\frac{67.2}{2}\times 0.1=3.36L[/tex] of [tex]O_2[/tex]
b. [tex]3\times 22.4L=67.2L[/tex] of [tex]O_2[/tex] react with = [tex]4\times 55.8=223.2g[/tex] of iron
Thus 10.0 L of [tex]O_2[/tex] react with = [tex]\frac{223.2}{67.2}\times 10=33.2g[/tex] of iron
Bond energies can be used to estimate the energy of a reaction. Why is this only an estimate?
A) It's difficult to measure such a smal amount of energy.
B) The bonds in all molecules are the same, but not all molecules have bonds that are easily measured.
C)The same bond in a different molecule has a different energy. For example, O-H in water versus ethanol has different energies.
D) It's difficult to isolate an individual bond.
Answer:
C)The same bond in a different molecule has a different energy. For example, O-H in water versus ethanol has different energies.
Explanation:
This is true going by the the statement about the bond energies and the bonding being different among the various elements. In the example given which is between ethanol and water, the bonds which exist among the elements is stronger in water than in ethanol. That is why, ethanol is easily combustible than water.
Answer:
The same bond in a different molecule has a different energy. For example, O-H in water versus ethanol has different energies.
Explanation:
How many moles in 6.57 x 10^24 formula units of NaCl?
0.092 moles
10.91 moles
3.96 X 10^49 moles
145 moles
Answer:
3.955*10^48
Explanation:
1 mole of a substance gives 6.02*10^23/6.57*10^24 will give x then cross multiply the answer. is 3.955*10^48
Which circuit would light the light. A or B
Answer:
B
Explanation:
you can tell by looking at the image lol the wires have to be connected
(brainliest please? c:)
( although its fine if not im just glad to have helped )
Answer:
The answer is B
Explanation:
suppose you start out with only reactants in a rigid container. if the initial concentration of SO2Cl2(g) is 0.543 M, and 43.6% of this initial concentration remains when the system has reached equilibrium, what are the equilibrium concentrations of each gas in the system
Answer:
Explanation:
From the information given:
The Chemical equation is:
[tex]SO_2Cl_{2(g)} \iff SO_{2(g)} + Cl_{2(g)}\\[/tex]
since 43.6% of the initial concentration remains at equilibrium
Then; the amount of [tex]SO_2Cl_2[/tex] that is being reacted is:
= 0.543 × (100 -43.6)%
= 0.306 M
The ICE table can be computed as follows:
[tex]SO_2Cl_2[/tex] ⇔ [tex]SO_{2(g)[/tex] + [tex]Cl_{2(g)[/tex]
I 0.543 0 0
C 0.306 +0.306 0.306
E 0.237 0.306 0.306
[tex]K_c = \dfrac{[SO_2] [Cl_{2}]}{[SO_2Cl_2]}[/tex]
[tex]K_c = \dfrac{0.306 \times 0.306}{0.237}[/tex]
[tex]K_c = 0.995[/tex]
Thus; the concentration at equilibrium for the species are:
[tex]SO_2Cl_2[/tex] = 0.237 M
[tex]SO_{(2g)[/tex] = 0.306 M
[tex]Cl_{2(g)[/tex] = 0.306 M
A 51.1g sample of brass is put into a calorimeter (see sketch at right) that contains 250.0g of water. The brass sample starts off at 95.4°C and the temperature of the water starts off at 25.0°C. When the temperature of the water stops changing it's 26.4°C. The pressure remains constant at 1atm.
Required:
Calculate the specific heat capacity of brass according to this experiment.
Answer:
0.415 j/g°C
Explanation:
Given that :
Mass of water, m1= 250.0 g
Temperature of water, T1= 25°C
Specific heat capacity of water, C= 4.184 J/g°C
Mass of brass , m2= 51.1g
Temperature of brass = 95.4°C
Specific heat capacity of brass , c2=?
Final temperature = 26.4°C
Heat lost by brass = Heat gained by water
mc(dT) = mc(dT)
51.1 * c * (95.4 - 26.4) = 250 * 4.184 * (26.4 - 25)
51.1 * 69 * c = 250 * 4.184 * 1.4
3525.9c = 1464.4
c = 1464.4 / 3525.9
c = 0.4153265
c = 0.415 j/g°C
Specific heat capacity of Brass for the experiment = 0.415 j/g°C
What are simple sugars
Answer:
Simple sugars are a type of carbohydrate.
Explanation:
Carbohydrates are one of the three basic macronutrients — the other two being protein and fat. Simple sugars are found naturally in fruits and milk, or they can be produced commercially and added to foods to sweeten, prevent spoilage, or improve structure and texture.
Explain how it's possible that warm temperatures can cause more snow to happen.
What animal has a see through body?
Decide whether a chemical reaction happens in either of the following situations. If a reaction does happen, write the chemical equation for it. Be sure your chemical equation is balanced and has physical state symbols. situation chemical reaction.
A strip of solid magnesium metal is put into a beaker of 0.042M SnCl3 solution.
Answer: [tex]3Mg(s)+2SnCl_3(aq)\rightarrow 3MgCl_2(aq)+2Sn(s)[/tex]
Explanation:
Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.
A more reactive element is one which can easily lose or gain electrons as compared to the other element.
As Magnesium is more reactive than tin, it can easily displace tin from its salt solution [tex](SnCl_3)[/tex] and form magnesium chloride and tin in elemental form.
The balanced chemical equation is:
[tex]3Mg(s)+2SnCl_3(aq)\rightarrow 3MgCl_2(aq)+2Sn(s)[/tex]
