Answer:
A
Explanation:
Trust me I take the Quiz
Help for brainliest
Answer:
those things that looks like cristals
2
A chart with the densities of four metals is shown.
Metal
Density (gicm')
Titanium
4.5
Zinc
7.1
Nickel
88
Silver
10.5
Students were given a sample of an unknown metal and told to determine
its density. They measured its mass as 26.4 g and its volume as 3.0 cm?
Use the chart to determine which metal the students were given.
Answer:
mass(m)=26.4g
volume (v)=3.0cm²
we have
density =m/v=26.4/3=8.8g/cm³
since it is equal to density of nickel.
Option C nickel is a required answer.
Answer:
[tex]\huge\boxed{\fcolorbox{green}{yellow}{option \: \: c}}[/tex]
How is stoichiometry used to calculate energy absorbed when a mass of
solid melts?
O A. Grams solid x mol/g * A Hreaction
B. Grams solid x mol/g * A Hp
C. Grams solid x mol/g * A Hfusion
O D. Grams solid x mol/g * A Hvap
Answer: Option C is correct
Grams solid x mol/g * A Hfusion
Explanation:
This is because from fusion is associated to melting and this is a process where solid particles or substances goes through transition phase and turn to liquid.
There for the stoichiometry is used to calculate energy absorbed when solid mass melt with the formula Grams solid x mol/g * A Hfusion.
2. If the half-life of Francium-233 is 22 minutes, how much time must elapse in order for 60 grams of a 64 gram
sample to undergo decay? In other words, after how many minutes will you only have 4 grams of the original isotope
remaining?
Answer:
88 minutes
Explanation:
64 g ---> 32g ---> 16g ---> 8 g ---> 4 g
So in total, we have 4 half lives to reach 4.0 g
therefore, 4 x 22 minutes = 88 minutes
88 minutes or four half lives are required to have 4 grams of the original isotope remaining.
What is half life?Half -life of a substance is defined as the time which is required for half of the quantity of a radioactive substance to get decayed.It is a term which is used in nuclear chemistry for describing how quickly unstable atoms undergo radioactive decay into other nuclear species by emitting particles or the time which is required for number of disintegrations per second of radioactive material to decrease by one half of its initial value.
During first half life= 64 g of isotope is present , during second half life 1/2×64=32 g of isotope is present, during third half life 1/2×32=16 g of isotope is present.during fourth half life 1/2×16=8 g of isotope is present.
As 1 half life is 22 minutes 4 half lives=4×22=88 minutes.
Thus, 88 minutes are requires for 4 g of sample to remain.
Learn more about half life,here:
https://brainly.com/question/24710827
#SPJ2
Balance the Chemical Equation. Fill in the Missing Coefficients. GeF3 + Cs = CsF + Ge
What is a jet stream. in your own words but be more detailed about what you say.
(don't send a link)
no links pls it’s very unhelpful
answer : i don’t knowww :)
Right spelling:
Answer: I don’t know. :)
Determine the grams of water produced when 250 grams of barium hydroxide react
with 125 grams of HCI. Refer to the balanced equation below.
Ba(OH)2 (aq) + 2HCl (aq) --> 2H2O (l) + BaCl2 (aq) (balanced)
Answer:
Explanation:
Ba(OH)₂ (aq) + 2HCl (aq) --> 2H₂O (l) + BaCl₂ (aq)
171 g 2 x 36.5 g 2 x 18 g
73 g of HCl reacts with 171 g of Ba(OH)₂
125 g HCl reacts with 171 x 125 / 73 g of Ba(OH)₂
= 292.8 g of of Ba(OH)₂
Ba(OH)₂ available is 250 g , so it is the limiting reagent .
171 g of Ba(OH)₂ forms 36 g of water
250 g of Ba(OH)₂ forms 36 x 250 / 171 g of water
= 52.63 g of water.
When 0.875 g. of magnesium was heated in air, 1.25 g. of magnesium oxide
(MgO) was produced. How much oxygen must be added?
Answer:
1. What is the coefficient for calcium in the balanced equation?
2 Ca + 5 NaOH → 4 Na + 2 Ca(OH)2
2. The burning of 20.0 g of acetylene (C2H2) produces what mass of carbon dioxide? You must
write the equation, balance it and solve the mass-mass problem.
a. Balanced equation:
2 C2H2 + 5 O2 4 CO2 + 2 H2O
Explanation:
If some salt were accidently spilled as it was transferred from the balance to the cup would your calculated enthalpy of solution of the salt be too high or too low
Answer:
It would be to low
Explanation:
If some salt were accidently spilled as it was transferred from balance to cup calculated enthalpy of solution of salt be too low as there will be loss in mass which would lead less solubility of salt and hence less enthalpy.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
Learn more about solubility,here:
https://brainly.com/question/29589228
#SPJ5
Can magic 8 ball wash with water?
PLEASE HELP ME If a radioactive substance has an initial mass of 50 grams
and its mass halves every 5 years, what is the number of
grams remaining after 20 years?
Answer: [tex]3.125\ g[/tex]
Explanation:
Given
Initial mass [tex]A_o=50\ g[/tex]
half-life is [tex]T_{\frac{1}{2}}=5\ years[/tex]
At any time the left amount is given by
[tex]A=A_o2^{-\dfrac{t}{T_{\frac{1}{2}}}}\\\\\text{Insert the values}\\\\A=50\cdot 2^{-\dfrac{20}{5}}\\\\A=50\cdot 2^{-4}\\\\A=\dfrac{50}{16}\\\\A=3.125\ g[/tex]
How much of a 10 M solution is needed to make 1 liter of a 1M solution?
a. 1ml
b. 1000ml
c. 10ml
d. 100ml
i dont know I hope someone knows soon take care
According to molar concentration, 100 ml of 10 M solution is needed to make 1 liter of a 1 M solution.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of two solutions, molar concentration is found out by, M₁V₁=M₂V₂.
On substitution in above formula, V₁=1×1/10=0.1 L=100 ml.
Thus, 100 ml of a 10 M solution is needed to make 1 liter of a 1 M solution.
Learn more about molar concentration,here:
https://brainly.com/question/21841645
#SPJ2
An atom of element X has an atomic number of 11 and a mass number of 23. .
a) What is the definition of atomic number?
b) How many protons, electrons and neutrons are in this atom?
c) A different atom of X has an atomic number of 11, but a mass number of 24. Give a
name for these two forms of X.
d) Would these two atoms have similar chemical properties? Give a reason for your
answer.
Answer:
ssaasasasassdsdsdafdftrga*b*y/a la 3
Explanation:
Answer:
a) the number of protons in an atom
b) 11 protons, 11 electrons and 12 neutrons.
c) Isotope
d) yes, they still have the same number of protons and electrons.
Explanation:
b) Number of neutrons = mass number - atomic number
Atoms have the same number of electrons and protons
c) isotopes are atoms with the same number of protons but a different number of neutrons.
Hope this helped !
During a combustion reaction, 9.00 grams of oxygen reacted with 3.00 grams of CH4.
What is the amount of the leftover reactant?
0.74 grams of methane
0.89 grams of methane
1.22 grams of oxygen
1.45 grams of oxygen
Answer:
0.74
Explanation:
this is the correct answer. I followed a correct answer that had the same probelm with different values, swithxed it with mine, and got 0.75. So its basically 0.74
How many joules of heat are needed to raise the temperature of 62.0 g of ethylene glycol from 13.1 C to 40.5C?
Answer:
Q = 4133.2 J
Explanation:
Hello there!
In this case, since these calorimetry problems are based off the following heat equation involving heat (Q), mass (m), specific heat (C) and temperatures (T):
[tex]Q=mC(T_2-T_1)[/tex]
Thus, we plug in the given variables to obtain:
[tex]Q=62.0 g*2.433 \frac{J}{g\°C}* (40.5\°C-13.1\°C)\\\\Q=4133.2J[/tex]
Regards!
Answer is D
Relatively slow rates of chemical reaction are associated with which characteristic?
A)
High temperature
B)
Low activation energy
C).
The presence of a catalyst
D)
Strong bonds in reactant molecules
Option D : Strong bonds in reactant molecules
The strong bonds in reactant molecules sometimes needs extra energy to weaken the bond and proceed the reaction. Hence, option D is correct.
What is reaction rate ?The rate of a reaction is the rate of decrease in concentration of the reactants or decrease in concentration of the reactants or increase in the concentration of the products.
The minimum energy required to overcome the barrier potential of a reaction is called its activation energy. Hence, lower the activation energy higher will be the reaction rate.
High temperature and presence of catalyst also leads to higher rate. Strong bonds in reactants needs higher energy to weaken the intermolecular force. Thus, slower the reaction rate.
Find more on reaction rate:
https://brainly.com/question/8592296
#SPJ6
How would the number of atoms in a 2.02g sample of hydrogen compare to the number of atoms in a 32.00g sample of oxygen
Answer:
Number of atoms is equal.
Explanation:
1 mol of anything contains NA particles.
NA is known as Avogadro's number, 6.02×10²³
We determined the moles of each compound. Both molecules are dyatomic,
H₂ → 2.02 g . 1mol / 2.016 g = 1 mol
O₂ → 32 g . 1mol / 32g = 1 mol
Both have the same amount of moles.
In conclussion, the number of atoms is the same in both samples.
Consider an ideal gas contained in a cylinder with the volume 34.4L, temperature 667K and pressure 2atm.What will be pressure of the gas if it is heated at 1000k and the volume becomes 50L.
Given :
An ideal gas contained in a cylinder with the volume 34.4L, temperature 667K and pressure 2 atm.
To Find :
What will be pressure of the gas if it is heated at 1000k and the volume becomes 50L.
Solution :
We know, by ideal gas equation :
[tex]Pv = nRT[/tex]
Now, in the given question only their are two state and also their is no leakage so amount of gas is also constant.
So,
[tex]\dfrac{P_1V_1}{T_1} = \dfrac{P_2V_2}{T_2}\\\\\dfrac{2\times 34.4}{667} = \dfrac{P_2 \times 50}{1000}\\\\P_2 = \dfrac{2\times 34.4 \times 1000}{667 \times 50}\ atm\\\\P_2 = 2.06 \ atm[/tex]
Therefore, the pressure of gas is 2.06 atm.
Find the total pressure (in atm) of a mixture that contains 3 gases with the following partial pressures. Gas A is 4.2atm, Gas B is 780 mmHg, Gas C is 250.00kPa
Answer: The total pressure of given mixture that contains 3 gases is 7.68 atm.
Explanation:
Given: Partial pressure of gases is:
Gas A = 4.2 atm
Gas B = 780 mm Hg
Convert mm Hg into atm is as follows.
[tex]1 mm Hg = 0.00131579 atm\\780 mm Hg = 780 mm Hg \times \frac{0.00131579 atm}{1 mm Hg}\\= 1.02 atm[/tex]
Gas C = 250 kPa
Convert kPa into atm as follows.
[tex]1 kPa = 0.00986923 atm\\250 kPa = 250 kPa \times \frac{0.00986923 atm}{1 kPa}\\= 2.46 atm[/tex]
Total pressure is the sum of partial pressures of gases present in the mixture.
Therefore, total pressure of given mixture is calculated as follows.
[tex]P_{total} = P_{A} + P_{B} + P_{C}\\= 4.2 atm + 1.02 atm + 2.46 atm\\= 7.68 atm[/tex]
Thus, we can conclude that the total pressure of given mixture that contains 3 gases is 7.68 atm.
The transmission of thermal energy that is caused by the flow of a fluid’s particles. It can only occur with liquids and gases is...
Which describes the greatest difference between gases and solids?
A. Solids feel softer than gases.
B. Gases are darker colors than solids.
c. Solids have stronger odors than gases.
D. Gases usually weigh less than solids.
Answer:
D)Gases usually weigh less than solids.
Answer:
D) Gases usually weigh less than solids
Explanation:
Gases don't have weight and solids do which automatically makes gases lighter because they don't have a mass like a solid.
what are some examples of long term environmental changes???
Answer: A long-term environmental change is... ice age, deforestation, urbanization, Earth's orbit, Sun's intensity, global Warming, radioactive waste/pollution. Extinction of species could happen to anyone of the food webs in a long term change.
Explanation:
PLEASE HELP ME :(((
What is the relative size and composition of the universe, a galaxy, and a solar system?
Answer:
about 93 billion light years
Explanation:
The observable Universe is, of course, much larger. According to current thinking it is about 93 billion light years in diameter.
Answer:
93 miles
Explanation: We can determine the distance to the sun using the time light takes to get to Earth. Just multiply the speed of light by the amount of time it takes light to get to Earth. That's 500 seconds.
186,282 miles per second x 500 seconds = 93,141,000 miles
The sun is about 93 million miles away from Earth. It will take our fastest space shuttle moving at a constant maximum speed about 108 days to travel this same distance.
A student dissolves 10 grams of sugar in enough water to make 25 ml of solution. What is the concentration of the solution
Answer: The concentration of given solution is 11.68 M.
Explanation:
Given: Mass of solute = 10 g
Volume of solution = 25 mL
Convert mL into L as follows.
[tex]1 mL = 0.001 L\\25 mL = 25 mL \times \frac{0.001}{1 mL}\\= 0.025 L[/tex]
Number of moles is the mass of substance divided by its molar mass. The moles of sugar (molar mass = 342.3 g/mol) is as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{10 g}{342.3 g/mol}\\= 0.0292 mol[/tex]
Molarity is the number of moles of solute present in a liter of solution.
Hence, concentration of given solution is calculated as follows.
[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.0292 mol}{0.025 L}\\= 11.68 M[/tex]
Thus, we can conclude that the concentration of given solution is 11.68 M.
If an amine functional group is added to an organic compound, the name of the compound will begin with
Answer for a apple it would be happle
xplanation:
Use the dichotomous key to identify these plant leaves.
Leaves from which plant are shown?
pine
catalpa
dogwood
maple
Answer:
catalpa
Explanation:
i took the test
down there (pls hurry!!)
give me the type of reactions ___ CuCO3 → ___ CuO + ___ CO2
Balance the following equations.
Answer:
A) Mg + H2SO4 → MgSO4 + H2
B) CaCO3 + 2HCl → CaCl2 + H2O + CO2
C) CaO + H2O → Ca(OH)2
D) 3Ag + 4HNO3 → 3AgNO3 + H2O + NO2
Explanation:
A) Mg + H2SO4 → MgSO4 + H2
The equation is already balanced because the number of each element in the left hand side is already equal to that in the right hand side.
B) CaCO3 + 2HCl → CaCl2 + H2O + CO2
This equation is balanced by putting 2 in front of HCl on the left hand side to balance the elements on the right hand side.
C) CaO + H2O → Ca(OH)2
Thus equation is already balanced because the number of each element in the left hand side is already equal to that in the right hand side.
D) 3Ag + 4HNO3 → 3AgNO3 + H2O + NO2
This equation is balanced by putting 3 in front of Ag and 4 in front of HNO3 on the left hand side while we put 3 in front of AgNO3 on the right side to balance the elements on the right hand side.