Answer:
17.6%
Explanation:
%age yield is = actual yield /percentage yield ^100
What is a balanced nuclear equation for the alpha decay of Strontium-90?
Answer: The balanced nuclear equation for the alpha decay of Sr-90 is [tex]_{38}^{90}\textrm{Sr}\rightarrow _{36}^{86}\textrm{Kr}+_2^4\alpha[/tex]
Explanation:
A nuclear reaction is defined as the reaction in which the changes in the nucleus of an atom take place and usually form a different element. The types of decay processes are:
Alpha decayBeta-decayGamma decayAlpha decay is the process in which a heavy nucleus decays into a light nucleus with the release of an alpha particle. This alpha particle carries a charge of +2 units and has a mass of 4 units. It is also known as the helium nucleus. The general equation for this decay process is:
[tex]X_Z^A\rightarrow Y_{Z-2}^{A-4}+\alpha _2^4[/tex]
The nuclear equation for the alpha decay of strontium-90 isotope follows:
[tex]_{38}^{90}\textrm{Sr}\rightarrow _{36}^{86}\textrm{Kr}+_2^4\alpha[/tex]
What is the enthalpy of reaction?
O A. The amount of mass involved in a reaction
O B. The heat released or absorbed in a reaction
C. The amount of heat a substance can hold
D. A measure of the temperature of a system
Answer:
Enthalpy is the amount of heat released or absorb. The total enthalpy can be found by subtracting the products' enthalpy by the reactants' enthalpy
What is the volume of 2.66 x 10^23 molecules of N2 gas at STP? PLEASE ANSWER WITH WORK! ILL GIVE BRAINLIEST
Answer:
1100L.
Explanation:
The strength of the gravitational attraction depends on the mass of the objects involved and the distance between them. The gravitational force between two objects will be lowest in which of the following situations?
A. Both objects have small masses and are close together.
B. One object has a large mass, and the objects are close together.
C. Both objects have large masses and are close together.
D. Both objects have small masses and are far apart.
Answer:
d sguro
Explanation:
I'm not sure kung ayan ba
Witch two chemists organized the elements based on properties suck as how the elements reacts or whether they are solid or liquid
Answer:
Antoine Lavoisier and Johann Wolfang Döbereiner organized the elements based on properties such as how the elements reacts or whether they are solid or liquid.
Explanation:
The periodic table of the elements as we have it today was developed as a result of the work of several notable centuries who lived centuries apart, all of who made notable contributions to development of the modern periodic table in use today.
In 1789, Antoine Lavoisier, a French Chemist provided a definition of elemets which he defined as a substance whose smallest units cannot be broken down into a simpler substance. He further grouped the elements into two as metals and nonmetals.
In 1829, German physicist Johann Wolfang Döbereiner arranged elements in groups of three in increasing order of atomic weight and called them triads. His arrangement owasf elements into triads was based on his observation of similarities in physical and chemical properties of certain elements.
John Newlands, a British Chemist was the first to arrange the elements into a periodic table with increasing order of atomic masses.
In 1869, Russian chemist Dmitri Mendeleev developed a periodic table which provided a framework the modern periodic table. He arranged the elements according to their atomic weight, leaving gaps for elements that were yet to be discovered.
The modern periodic table arranges elements based on increasing atomic number.
How much heat is required to raise the temperature of 16.0 grams H2O from 5.000C to 75.00C? Below is a list of constants.
specific heat for H2O(s) = 2.1 J/g0C
specific heat for H2O(L) = 4.18 J/g0C
specific heat for H2O(g) = 1.7 J/g0C
\bigtriangleup H△Hvap = 40.7 kJ/mol
\bigtriangleup H△Hfus = 6.01 kJ/mol
5.34 J
260 J
4680 J
2350 J
Answer:
The amount of heat required is 4681.6 J.
Explanation:
mass, m = 16 g = 0.016 kg
initial temperature, T = 5 C
final temperature, T' = 75 C
specific heat, c = 4.18 J/g C
The amount of heat required is
H = m c (T'- T)
H = 16 x 4.18 x (75 - 5)
H = 4681.6 J
I have a exam please answer fast
Answer:
C
[tex] \triangle \: H {}^{ \theta} _{s} = lattice \: energy + hydration \: energy \\ = + 2526 + ( - 2003 + (2 \times - 340)) \\ + 2526 - 2683 \\ = - 157 \: kjmol {}^{ - 1} [/tex]
Describe the four states of matter.
Elias read a book about California earthquakes. He then wrote a three-
paragraph report about the book. Which of the following active reading
strategies did Elias use?
A. Making mental images
B. Drawing inferences
C. Summarizing
D. Making predictions
Calculate the total amount of energy required in calories to convert 50.0 g of ice at 0.00 degrees Celsius to steam at 100. degrees Celsius.
Specific heat capacity of water is 1.00 cal/g OC
Hfusion = 80 cal/g OC and Hvap = 540 cal/g OC
Write the complete equation you will use. 1 point
Substitute the values in the equation in step 1. 1 point
Report the math answer with 3 sig figs and the correct unit. 1 point
Answer:
HFusion*mass + Spec.Heat*mass*ΔT + HVap*mass
80cal/g*50.0g + 1.00cal/g°C*50.0g*(100°C-0°C) + 540cal/g*50g
3.60x10⁵cal
Explanation:
Using the HFusion we can find the heat needed to convert the ice to liquid water.
With specific heat capacity we can find the heat needed to increase the temperature of water from 0 to 100°C.
With HVap we can find the heat to convert the liquid water into steam.
The equations are:
HFusion*mass + Spec.Heat*mass*ΔT + HVap*massComputing the values:
80cal/g*50.0g + 1.00cal/g°C*50.0g*(100°C-0°C) + 540cal/g*50g36000cal =
3.60x10⁵calan unknown gas diffuses 1.25 times faster than CO2 gas. What is the molar mass of the unknown gas?
Answer:
28.16 g/mol
Explanation:
From Graham's law;
Let the rate of diffusion of gas X be 1.25
Let the rate of diffusion of CO2 be 1
Molecular mass of gas X= M
Molecular mass of CO2 = 44g/mol
1.25/1=√44/M
(1.25/1)^2 = 44/M
1.5625 = 44/M
M= 44/1.5625
M= 28.16 g/mol
22)When iron rusts in air, iron(III) oxide is produced. How many moles of oxygen will react
with 2.4 mol of iron ?
4Fe(s) + 3O2(g) → 2Fe2O3(s)
A)1.2 mol
B)1.8 mol
C)2.4 mol
D)3.2 mol
E)4.8 mol
show work
Answer:
B
Explanation:
)When iron rusts in air, iron(III) oxide is produced. How many moles of oxygen will react
with 2.4 mol of iron ?
B)1.8 mol
Matter takes up _____.
(a) Space and temperature
(b) Space and heat
(c) Space and mass
(d) Heat and temperature
You will not measure the enthalpy of the reaction of ______ in the coffee cup calorimeter because this reaction involves gases. Instead, you will use a well-known published value.
HCI and MgO
HCI and Mg
H2 and O2
Answer:
H2 and O2
Explanation:
A coffee cup calorimeter is basically a type of calorimeter that operates at constant pressure. The heat measured in the calorimeter is equal to the change in enthalpy of the reaction.
This type of calorimeter is apt for reactions involving solutions where there is little or no change in volume.
It is not generally applicable to gas phase reactions such as the reaction between H2 and O2.
Answer:
You will not measure the enthalpy of the reaction of
✔ H2 and O2
in the coffee cup calorimeter because this reaction involves gases. Instead, you will use a well-known published value.
C. H2 and O2
Is Correct
an atom of an element is represented as 39/19x, write its
(1) number of protons
(2)number of neutrons
(3)Electric configuration
(4)number of valence electrons
Answer:
Solution :
Lithium
Z = 3
P = 3
E = 3 = (2, 1) p=3
A = 7 n=4
P + n = A
3 + n = 7
N = 4

Carbon
Z = 6
P = 6
E = 6 = (2, 4) p=6
A = 12 n=6
P + n = A
6 + n = 12
N = 6
PLZ HELP!!! What mass of [tex]SrF_{2}[/tex] can be prepared from the reaction of 10.0g [tex]Sr(OH)_{2}[/tex] with excess HF? THANK U!!
Answer:
Approximately 10.5g or 10.4g [tex]SrF_{2}[/tex]
Which of these is not a mixture?
A) Salt
B) Cooking oil
C) Tea leaves
D) Milk
ty
Answer:
the answer is salt because it has a uniform and definite composition
Explanation:
Michael is studying the factors that affect corrosion of metals. He wants to test the effect that different concentrations of an acid will have on the corrosion of a metal. As he sets up and completes his experiment, which of the following experimental designs would be most likely to help him answer his question? A. Allow several metal samples to soak in different amounts of acid of a single concentration and then measure the amount of corrosion on each. B. Prepare solutions of different acid concentrations, measure 50 milliliters of each into different beakers, and place metal samples of different types but of the same mass into the beakers. C. After allowing several small metal sheets to be exposed to different acid concentrations, measure the surface area of each that is corroded. D. After allowing a small metal sheet to be exposed to one acid concentration, place it in different acid concentrations, then measure the surface area that is corroded.
Answer:
B. Prepare solutions of different acid concentrations, measure 50 milliliters of each into different beakers, and place metal samples of different types but of the same mass into the beakers.
Explanation:
Since Michael is studying the factors that affect corrosion of metals, and wants to test the effect that different concentrations of an acid will have on the corrosion of a metal, using different acid concentrations of the same volume on different metal samples of the same size would give a much better than all the other options because, a standard volume of acid is used and also a standard mass of metal is used. So, the effect can be measured quantitatively since we have the same quantity of sample.
So, option B is the answer
Which of the following describes the reactants of a chemical reaction?
A. The substances that dissolve
B. The resulting substances
C. The atoms that are rearranged
D. The original substances
Look at the activity series and select which two of the following reactions would happen on their own. (Remember, if the lone element is more active than the metal in the compound, the lone element will react and replace the metal in the compound.) Lithium (Li)
Potassium (K)
Calcium (Ca)
Sodium (Na)
Aluminum (Al)
Zinc (Zn)
Iron (Fe)
Tin (Sn)
Lead (Pb)
(Hydrogen) (H)
Copper (Cu)
Silver (Ag)
Gold (Au)
A.
2Li + ZnBr2 ->2LiBr + Zn
B.
Al + 3LiCl ->AlCl3 + 3Li
C.
Sn + ZnSe ->SnSe + Zn
D.
3Ca + Al2O3 ->2Al + 3CaO
Answer:
2Li + ZnBr2 ->2LiBr + Zn
3Ca + Al2O3 ->2Al + 3CaO
Explanation:
Spontaneous reactions are reactions that can happen on their own. For a spontaneous reaction to occur, a metal that is higher in the activity series must displace a metal that is lower in the activity series from its solution and not vice versa.
If we look at the two reactions selected in the answer, lithium is above zinc in the activity series and calcium is above aluminum in the activity series hence the two reactions occur spontaneously.
copper +sulfur + oxygen =
Which of these is true about a pH meter?
It is inexpensive to use.
It measures pH indirectly.
It does not require calibration.
It can be used in any acid-base titration.
Answer:
That is, a pH meter is useful in detecting or knowing the acidity (due to ions) or alkalinity (due to ions) of a solution. Thus, we can conclude that out of the given options it is true about a pH meter that it can be used in any acid-base titration
Answer: D. It can be used in any acid-base titration.
Explanation:
Does a reaction involving an acid and a base have to take place in a water environment? Justify your answer.
Answer:
YES!!!
Explanation:
Strong acids and strong bases are both strong electrolytes. In contrast, only a fraction of the molecules of weak acids and weak bases react with water to produce ions, so weak acids and weak bases are also weak electrolytes.
What plate forms a boundary with the African plate
Answer:
The Eurasian plate(another major plate), the Aegean sea plate and the Anatolian plate share the north border. The Antarctic plate that contributes to the south of the African plate, is also a major plate.
From lithium and cesium which is less electronegative?
Answer:Electronegativity, symbolized as χ, is the tendency of an atom to attract shared electrons (or electron density) to itself.
Explanation:
Answer:
Explanation:
The correct answer is cesium
Because If you look at the electronegativities of just Lithium and Cesium then you would notice that the shielding effect is more prevalent in Cesium, thereby reducing the electronegativity and affecting the reduction potential
7. A sample of methane gas (CH.) with a mass of 58 g is kept in a 1500 mL container at a temperature of 100. °C. What is the pressure of the gas?
Answer:
c i took the text
Explanation:
State three pieces of evidence from the diagram which indicate that the plant is pollinated by wind. ( 3 marks)
Your image is saying "Can't load image on this device."
At STP, what is the volume of 55.0 g of BF3?
Answer:
The volume of 55 grams of BF₃ is 18.1664 L.
Explanation:
If the molar mass of compound BF₃ is 67.81 [tex]\frac{grams}{mole}[/tex], then the number of moles 55 grams of compound contains is calculated as:
[tex]55 grams* \frac{1 mole}{67.81 grams} = 0.811 moles[/tex]
The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Then it is possible to apply the following rule of three: if by definition of STP 1 mole of a compound occupies 22.4 L, 0.811 moles of the compound occupies how much volume?
[tex]volume=\frac{0.811 moles* 22.4 L}{1 mole}[/tex]
volume= 18.1664 L
The volume of 55 grams of BF₃ is 18.1664 L.
How does radon move up through rock and soil?
ELECTRICITY IS ALLOWED TO PASS THROUGH ACIDIFIED WATER USING THE FOLLOWING EXPERIMENTAL SETUP.
QUESTION: IDENTIFY THE PROCESS
Answer: Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.
Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode.
Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode.The reaction for decomposition of water into oxygen and hydrogen is as follows:
Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode.The reaction for decomposition of water into oxygen and hydrogen is as follows:2H2O(l) -------> 2H2(g) + O2(g)
