Answer:
Answer here!
Explanation:
One controlled variable can be that they used the same setup, that is the constant between the two experiments. The manipulation was that Spallanzani used a flask without any air and a flask with air. The responding was or the dependent variable was to notice what had changed so in the experiment Spallanzani noticed that the flask with no air led to no microorganisms meaning that the theory of spontaneous generation is false.
The manipulated variable was the presence or absence of air in the flask. The responding variable was the growth of microorganisms in the broth. The controlled variable was the composition of the broth.
In Spallanzani's experiment, the manipulated variable refers to the factor that the scientist deliberately changes or manipulates. In this case, it was the presence or absence of air in the flasks. One flask had air sealed inside with the broth, while the other flask had no air present.
The responding variable is the factor that is observed or measured in response to the manipulated variable. In this experiment, the growth of microorganisms in the broth was the responding variable. Spallanzani checked for the presence or absence of microorganism growth in each flask.
The controlled variable is the factor that is kept constant or controlled throughout the experiment to ensure that it does not influence the results. In this case, the controlled variable was the composition of the broth used in both flasks. The broth composition was consistent, ensuring that any differences observed in microorganism growth could be attributed to the presence or absence of air.
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A cylinder is filled with 10.0 L of gas and a piston is put into it. The initial pressure of the gas is measured to be 273. kPa.
The piston is now pulled up, expanding the gas, until the gas has a final volume of 50.0 L. Calculate the final pressure of the gas. Be sure your answer has the
correct number of significant digits.
P2 = 54.6 kPa
Explanation:
Given:
V1 = 10.0 L. V2 = 50.0 L
P1 = 273 kPa. P2 = ?
We can use Boyle's law to solve this problem.
P1V1 = P2V2
Solving for P2,
P2 = (V1/V2)P1
= (10.0 L/50.0 L)(273 kPa)
= 54.6 kPa
helium gas (He) effuses ___ times faster than methane (CH4)
a. 1.80
b. 2.00
c. 2.20
d. 2.40
Answer:
b 2.00
Explanation:
I am pretty sure that is right
Zn + 2HCl → ZnCl2 + H2
How many moles of hydrogen are produced from the reaction of
6.0 moles of zinc?
Answer:
6
Explanation:
6.0mol ( 1 mol H2/ 1 mol Zn ) = 6.0 mol of H2
H2 is hydrogen gas (hydrogen in the air).
How is a TV like our brain?
Answer:
Explanation:
Because your brain and the TV are programed to do certain things. As if you're going back into a memory, and you're simply rewatching a season of Beyblade: Metal Fusion on the TV.
A gas occupies 4.31 liters at a pressure of 150 mm Hg. Determine the volume if the pressure is increased to 725 mm Hg.
Answer:
0.89 L
Explanation:
Applying,
Boyle's Law,
PV = P'V'..................... Equation 1
P represent initial pressure, V represent initial volume, P' represent final pressure, V' represent final volume
Make V' the subject of the equation
V' = PV/P'.............. Equation 2
From the question,
Given: P = 150 mm Hg, V = 4.31 liters, P' = 725 mm Hg
Substitute these values into equation 2
V' = (150×4.31)/725
V' = 0.89 L
In order to calculate the number of neutrons you must subtract the what from the what?
Answer:
You take the atomic, or proton number of the element, and you subtract it from the element's mass number.
Answer:
protons
Explanation:
neutrons and protons make up the mass of the atom
how to calculate the mass percent of hydrogen
Answer:
divide the mass of element in 1 mole of the compound by the compound's molar mass and multiply the answer by 100.
Explanation:
take the molar mass of hydrogen in the water molecule, divide by the total molar mass of water, and multiply by 100.
does it help?
Suppose you used a needle to poke two holes in a sealed tube of toothpaste. One hole near the cap and one hole is in the middle of the tube. You then squeeze the tube at the base. Compare how the toothpaste will leave each needle hole. Be sure to explain using theory, why this happens.
Answer:
done this before in my science class
Explanation:
the hole by the cap will have slightly more coming out at first due to all the toothpaste pushing forward, but over time, the middle will get more do to all the front end of the toothpaste being pushed out first
(sorry if that sounded confusing im tired, heres a cat)
The hole by the cap will have slightly more coming out at first due to all the toothpaste pushing forward, but over time, the middle will get more do to all the front end of the toothpaste being pushed out first.
What is toothpaste?Toothpaste is a key part of your daily oral hygiene routine. Along with your toothbrush and floss it helps to remove food debris and plaque from your teeth and gums.
Toothpastes can come in a gel, paste or powder form. While the ingredients differ slightly, all toothpastes contain the same general components.
With some help from your toothbrush, these help to remove debris and surface stains. This ingredient helps to prevent water loss, and keeps your toothpaste from drying out or getting gummy. This is what gives your toothpaste a little bit of sweetness, and that minty fresh scent. Since these do not contain sugar, they also do not promote tooth decay.
Therefore, The hole by the cap will have slightly more coming out at first due to all the toothpaste pushing forward, but over time, the middle will get more do to all the front end of the toothpaste being pushed out first.
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is sodium oxide an acidic oxide or a basic oxide
Answer:It a Basic oxide
Plz trust Me
Explanation:
Answer:
Sodium oxide is a simple strongly basic oxide. It is basic because it contains the oxide ion, O2-, which is a very strong base with a high tendency to combine with hydrogen ions. Reaction with water: Sodium oxide reacts exothermically with cold water to produce sodium hydroxide solution.
Explanation:
Atoms that have become negatively charged by gaining extra electrons are called
Answer:
CATION
Explanation:
If an atom has an equal number of protons and electrons, its net charge is 0. If it gains an extra electron, it becomes negatively charged and is known as an anion. If it loses an electron, it becomes positively charged and is known as a cation.
Calculate the amount of heat energy is needed to raise the temperature of 5.00 grams of lead from 25.0 to 35.0 degrees Celsius, if the specific heat capacity of lead is 0.129 J/g/C.
Answer: 6.45 Joules
Explanation: I just did it
Given the following equation: Na2O + H2O ---> 2 NaOH
How many moles of NaOH are produced from 1.02 moles of Na2O?
Answer:
2.04 moles
Explanation:
Since the ratio of Na2O to NaOH is 1:2, you multiply the number of moles by 2, equaling 2.04 moles.
gu khayo bhana m hunxa hola
Answer:
[tex] \huge\pink{\boxed{\mathfrak{Hola}}}[/tex]
I didn't understand the rest of your question, it's not in English or Spanish.
[tex]\huge\fbox{HôLLa}[/tex]
Describe how you could show that a compound is an acid
.What is the significance of genetic variation within the population of moths during and after the Industrial Revolution in London?
Answer:
The evolution of the peppered moth is an evolutionary instance of directional colour change in the moth. The frequency of dark-coloured moths increased at that time, an example of industrial melanism.
Explanation:
I did this on Savvas Realize got it right.
Genetic variation is said to be the difference in the hereditary sequence. After the industrial revolution, the frequency of the dark-colored moth increased dramatically more than the light-colored moths.
What is industrial melanism?
Industrial melanism was an example of the evolutionary effect that occurred in the moths where the dark-colored species were favored over the light-colored species of peppered moths.
Before the industrial population, light-colored moths were large in number which later decreased with an increase in pollution. This occurred due to an increase in the pollutants and dust deposition that altered the environment.
As the pollution increased over time the dark-colored moths became dominant and increased their population over time. This is an example of industrial melanism as the color of the body was the determining factor in survival.
Therefore, dark-colored moths were prevalent after the industrial revolution.
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How many moles are in 15.3 grams of KNO3?
Answer:
0.151 mol
Explanation:
molar mass of KNO3 = (39.1 + 14 + 3×16) g/mol = 101.1 g/mol
number of moles = mass/molar mass
n = m/M = 15.3 g/(101.1 g/mol) = 0.151 mol
Name the following alkyne:
A. propane
B. propene
C. propyne
D. methyne
The name of the alkyne which is given in the question with structure is propyne as in that 3 carbon atoms are present.
What are alkynes?Alkynes are those hydrocarbons in which triple bond is present between two adjacent carbon atoms.
In the given structure one triple bond is present between first two carbon atoms and then with this a single bonded carbon atom is also attached. As in the structure total three carbon atoms are present so prefix shoul be 'prop' and as this is an alkyne then name should be propyne.
Propane is wrong because it is used with single bonded hydrocarbons.Propene is also wrong as it is used with double bonded hydrocarbons.Methyne is also wrong as it is not a word that make any sesne.Hence name of compound is propyne.
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Propyne is the chemical name for the given alkyne. Therefore, the correct option is option C.
A triple bond exists between the carbon atoms in alkynes, a group of hydrocarbon molecules. They are given names based on the IUPAC (International Union of Pure and Applied Chemistry) guidelines for systematic nomenclature. Alkyne nomenclature's primary objective is to provide each compound a precise and distinctive name that accurately captures its structure. Based on the quantity of carbon atoms, the placement of triple bonds, and the presence of functional groups, alkyne compounds are named systematically.
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Whoever solves this right will get brainliest :3
Reaction 1 → Al + Zn²⁺ ⟶ Al³⁺ + Zn
Reaction 2 → Al³⁺ + Li ⟶ Al + Li⁺
To Find :-Substance OxidisedSubstance ReducedOxidizing Agent Reducing Agent Answers :-Reaction 1 :-
Substance Oxidised :- Al
Substance Reduced :- Zn²⁺
Oxidizing Agent :- Zn²⁺
Reducing Agent :- Al
Reaction 2 :-
Substance Oxidised :- Li
Substance Reduced :- Al³⁺
Oxidizing Agent :- Al³⁺
Reducing Agent :- Li
____________________Final Answers :-Reaction 1 :-
Al
Zn²⁺
Zn²⁺
Al
Reaction 2 :-
Li
Al³⁺
Al³⁺
Li
____________________Help me Pleaseeeeeeeee
drag
effect
friction
parachutes
surface area
streamlined
air
water
Energy is released when the nucleus of an atom splits and two smaller atoms are formed. What is the name of this process?
A. Electricity
B. Nuclear Fusion
C. Positron Particles
D. Nuclear Fission
Explanation:
It's (D), nuclear fission................
The decomposition of water into hydrogen gas Hy and oxygen gas Oz can be modeled by the balanced chemical equation
A)
H2 + 02 - H20
B)
H20 - H2 + O2
C) 2H2 + 02 - 2H20
D)
2H20 - 2H2 + O2
Answer:
D. ) 2H2O - 2H2 + O2
What is the new concentration of a solution after 250mL of 2.5M sulfuric acid is diluted to a final volume of 700mL?
Please show your work
Answer:
The new concentration of the solution is 0.89 M.
Explanation:
In chemistry, dilution is the reduction in concentration of a chemical in a solution. This is accomplished by adding more solvent to the same amount of solute.
So, in a dilution, the amount of solute does not vary, but the volume of the solvent varies: as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.
In a dilution the expression is used:
Ci*Vi = Cf*Vf
where:
Ci: initial concentration Vi: initial volume Cf: final concentration Vf: final volumeIn this case:
Ci= 2.5 M Vi= 250 mLCf=? Vf= 700 mLReplacing:
2.5 M* 250 mL= Cf* 700 mL
Solving:
[tex]Cf=\frac{2.5 M*250 mL}{700 mL}[/tex]
Cf= 0.89 M
The new concentration of the solution is 0.89 M.
Can everyone help me :)
Answer:
joules
Heat is the transfer of thermal energy from a system to its surroundings or from one object to another as a result of a difference in temperature. Heat is measured in joules (J).
Explanation: Mrk me brainliest please
Answer: Joules or calories
Give an example of Carbon atoms getting into the biosphere:
Answer:
Carbon in the biosphere
Explanation:
Carbon is found in the biosphere stored in plants and trees. Plants use carbon dioxide from the atmosphere to make the building blocks of food during photosynthesis. Carbon is found in the hydrosphere dissolved in ocean water and lakes. Carbon is used by many organisms to produce shells.
How much energy is released when 75g of liquid water is reduced from 65c to 0c and completely freezes?
Answer:
Q = 20377.5 Joules
Explanation:
Given the following data;
Mass = 75g
Initial temperature = 65°C
Final temperature = 0°C
Specific heat capacity of water = 4.18 J/g°C.
To find the quantity of heat released;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.
Substituting into the equation, we have;
[tex] Q = 75 * 4.18 * 65 [/tex]
Q = 20377.5 Joules
Which is not an example of a
parasite/host relationship?
A flea on a dog
A tick on a horse
A toad on a lily pad
A barnacle on a whale
Answer:
A toad on lily pad
Explanation:
have a great day
If an object is on top of a hill or in a position raised above the ground, it must have __________.
Answer:
The force applied to the object is an external force, from outside the system. When it does positive work it increases the gravitational potential energy of the system. Because gravitational potential energy depends on relative position, we need a reference level at which to set the potential energy equal to 0.
If an object is on top of a hill or in a position raised above the ground, it must have gravitational potential energy.
What is Potential Energy ?
In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors
If an object is lifted, work is done against the force of gravity.
When work is done energy is transferred to the object and it gains gravitational potential energy.
If the object falls from that height, the same amount of work would have to be done by the force of gravity to bring it back to the Earth’s surface.
Due to the Principle of Conservation of Energy we can say that:
Gravitational potential energy at the top = kinetic energy at the bottom
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A sample of an unknown metal has a mass of 120.4 g. As the sample cools from 90.5°C to 25.7°C, it releases 7020 J of energy. Usinf the chart below, what is the identity of the metal in the sample? Hint Calculate specific heat first Substance Specific Heat Water (liquid) 4.184 J/g °C 0.899 J/g °C 0.803 J/g °C 0.449 J/g °C a) Aluminum ) b) Granite Oc) Water d) Iron
Answer:
Explanation:
sheesh i wouldn’t know
1. How do scientific investigations begin?
conclusion
inquiry
testing
hypothesis
Answer:
Hypothesis is the answer
1.16g of methane burns completely with 4.16g of oxygen to form 3.52g of carbon dioxide and
water If the reaction obeys the law of conservation of mass, the weight of water formed is
Answer:
weight of H₂O formed = 2.3 grams H₂O (2 sig. figs.)
Explanation:
Rxn: CH₄(g) + 2O₂(g) => CO₂(g) + 2H₂O(g)
Given: 1.16g 4.16g 3.52g ? (g)
Moles: 1.16g/16g·mol⁻¹ 4.16g/32g·mol⁻¹ 3.52g/44g·mol⁻¹
= 0.0725mol. = 0.13mol. = 0.08mol. => ? (moles)
Limiting Reactant: Divide each mole value by related coefficient of balanced standard equation (that is, balanced with coefficients in lowest whole number ratios). The smaller value is the limiting reactant.
0.0725/1 0.13/2 0.080/1
= 0.0725 = 0.065 = 0.080
Limiting Reactant is O₂(g) => 0.065 is smaller value after dividing each mole value by related coefficient of balanced equation.
NOTE: When working problem, however, one must use the mole value calculated from given amount in grams. That is, in this case 0.13 mole O₂. The 'divide by related coefficient and check smaller value' is ONLY for identifying the limiting reactant. This trick works for ALL general chemistry problems.
Moles H₂O formed: Since the coefficient of the limiting reactant (O₂) equals the coefficient of water (H₂O), then the moles of water formed is 0.065 mole H₂O.
Weight (in grams) of H₂O formed:
Grams H₂O = moles H₂O x formula weight H₂O
= 0.13 mole H₂O x 18 g H₂O/mole H₂O
= 2.34 g H₂O (calculator answer)
= 2.3 g H₂O (final answer should be rounded to 2 sig. figs.) => form of final answer should be based on data in final computation having the least number of sig. figs.
Review: Sequence of calculations
Write and balance equation to smallest whole no. ratio of coefficients.If not in moles, convert given 'measured' data to dimension of moles. => moles = mass (g)/formula wt(g·mol⁻¹) => moles = volume of gas in Liters/Std Molar Volume (= 22.4L·mole⁻¹ at STP) => moles = no. of particles / Avogadro's No. (= 6.02 x 10²³ part's/mole)Determine Limiting Reactant => mole values of each compound given / related coefficient in standard equation => smallest value is L.R.Determine moles of unknown needed/used/formed from limiting reactant in moles and coefficient of unknown compound in standard equation given data values.=> moles of limiting reactant / coefficient of same cpd. in std. equation = unknown (X) / coefficient of same (unknown) cpd. in std. equation
=> cross multiply and solve for unknown (X)
=> L.R.(moles) / eqn. coef. of L.R. = X / eqn. coef. of X
=> (L.R.(calc'd moles)(eqn. coef. of X) = (X)(eqn. coef. of L.R.)
=> X (in moles) = (L.R.(calc'd. moles)(eqn. coef. of X) / (eqn. coef. of L.R.)
Convert X-answer in moles to desired dimension specified in problem.=> grams = moles x formula wt.
=> volume (L) = moles x std. volume (= 22.4L/mole)
=> #particles = moles x Avogadro's Number (= 6.02 x 10²³ parts/mole)