Answer:
the last answer is right.
Which sentence describes existing cells?
All cells, once formed, continue to live forever.
All cells come from previously existing cells.
All the cells that are on Earth have always been here.
All cells develop from the remains of other cells.
Convert 84 miles to kilometers (there are 0.6 miles in a kilometer)
using the method dimensional analysis
Answer:
Explanation:
Put the given unit on the bottom of the brackets.
84 miles [tex]\frac{1 km}{0.6 miles}[/tex] = 84/0.6 = 140 km
50. Carbon mono-oxide can be prepared by heating following substance with Conc. H2SO4. a. Oxalic acid b. Acetic acid c. Ethanoic acid d. All ic 252
A
Carbon monoxide gas can be prepared in lab by heating formic acid or oxalic acid with conc. H2SO4.
Procedure: Small amount of oxalic acid crystal is taken in a round- bottomed flask and all the apparatus are fitted as shown in figure. When conc. H2SO4 is poured in the flask through thistle funnel and heated then a mixture of CO and CO2 gas is formed. The mixture of gas is passed through a bottle containing NaOH solution where the CO2 gas is absorbed by NaOH.
2NaOH + CO2 → Na2CO3 + H2O
The pure CO gas is then collected in a gas jar by downward displacement of water.
value of MA is always lesser thàn 1 why?
Answer:
because the load arm is greater than the effort arm. As we know that when the load arm is greater than the effort arm, the mechanical advantage will always be lesser than one, which results in gain in speed
Identify each of the highlighted materials as an element, a compound, or a mixture, and explain your reasoning.
Answer:
These are compounds.
Explanation:
As it is formed by chemically bonding of two elements C ( carbon) and H (hydrogen) .
Its not a mixture because mixture is Just dispersed of diferrent elements or a compound which are not in fix ratioAnswer:
Butane and benzene are both compounds. They contain multiple elements bonded together in a specific ratio. Kerosene and gasoline are mixtures because they are combinations of several compounds. Oxygen is an element because it is made up of only one type of atom.
Explanation:
the element of group 1 are reactive but those of group 18 are inert, why
Answer:
Because elements of group 1 does not have stable electronic configuration and elements of group 18 have stable electronic configuration.
Explanation:
Because elements of group 1 do not contain stable electronic configuration and elements of group 18 include stable electronic configuration.
What are the element of group 1?Group 1 elements contain the alkali metals, Li, Na, K, Rb, Cs, and Fr. The alkali metals exist all soft, shiny, and metallic when cut. They react efficiently with water, have low melting points and densities, and are good conductors of electricity. They all include one valence electron that they lose easily to form ions. Noble gas exists as any of the seven chemical elements that create up Group 18 (VIIIa) of the periodic table. The elements exist as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).
The element of group 1 exist as reactive but those of group 18 exist as inert Because elements of group 1 do not contain stable electronic configuration and elements of group 18 include stable electronic configuration.
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PLZ HELP ME WITH MY WORK
Answer:
Explanation:
pretty sure its mixure.
True or false, The four units that must always be used when using the ideal gas are 44.0 liters
Answer:
for volume only liters can be used
Explanation:
how can we separate the sugar from sugar solution
Determine the grams of sodium chloride produced when 10 g of sodium react with 10 grams chlorine gas according to the equation 2Na + Cl2 = 2 NaCl
Answer:
16 g
Explanation:
Step 1: Write the balanced equation
2 Na + Cl₂ ⇒ 2 NaCl
Step 2: Identify the limiting reactant
The theoretical mass ratio (TMR) of Na to Cl₂ is 46:71 = 0.65:1.
The experimental mass ratio (EMR) of Na to Cl₂ is 10:10 = 1:1.
Since EMR > TMR, Cl₂ is the limiting reactant
Step 3: Calculate the mass of NaCl produced
The theoretical mass ratio of Cl₂ to NaCl is 71:117.
10 g Cl₂ × 117 g NaCl/71 g Cl₂ = 16 g NaCl
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Which statement describes the periodic law?
Help please now!
Answer:
Answer is: elements in the same group have similar chemical properties. Periodic law is the arrangement of the elements in order of increasing atomic number.
How many times more acidic is pH2 than pH4?
Answer:
100 times more acidic.
Explanation:
If you look at the pH scale, pH2 is 2 "jumps" away from pH4, therefore, pH2 is 100x more acidic than pH4.
Explain whether changing the ratio of baking soda and vinegar changes the amount of carbon dioxide produced. Include the evidence you used to reach your conclusion.
On changing the ratio of baking soda and vinegar changes the amount of carbon dioxide produced is true, because each species will depends on both reactants.
What is chemical reaction?Chemical reaction between baking soda and vinegar is shown below in the attached image in which the formation of carbon dioxide, water and sodium acetate takes place. So the formation of carbon dioxide depends on the baking soda and baking soda reacts with vinegar to form sodium acetate so change in the ratio will changes the amount of carbon dioxide.
Hence on changing the ratio of reactants and vinegar changes the amount of carbon dioxide.
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If 16.4 grams of calcium nitrate is heated as shown in the reaction:
2Ca(NO3)2 -> 2CaO + 4NO2 + O2.
Calculate the volume of nitrogen dioxide produced at STP.
Answer:
7.2
Explanation:
you first have to find the number of moles of nitrogen dioxide by using the number of moles for calcium nitrate and the mole to mole ratios
number of moles of calcium nitrate=mass/mm
=16.4/102
=0.16g/mol
then you use the mole to mole ratios
2 : 4
0.16: x
2x/2=0.64/2
x=0.32g/moles of nitrogen dioxide
then you use the formula for the volume
v=22.4n
=22.4×0.32
=7.2
I hope this helps
Assertion: Atomic mass of aluminium is 27 Reason: An atom of aluminium is 27 times heavier than 1 / 12th of the mass of the C – 12 atoms.
Answer:
i is the correct answer.
Explanation:
the RAM of aluminum is indeed 27. And since the RAM of substances are measured in terms of the C-12 isotope then R indeed explains why the RAM Al is 27.
Which statement is true about percent yield
The atomic mass of calcium is calculated by adding the mass (amount) of
A) Protons and Electrons
B) Protons and Neutons
C) Electrons and Neutons
D) Protons and Protons
Answer:
B. Protons and Neutrons
Answer:
Option"B" is correct.
MARK ME BRAINLISTS
Identify an element as a metal or a non-metal according to its position in the Periodic
Table
Answer:
Metals on the left of the Periodic Table.
Non-Metals on the top-right, plus Hydrogen.
hii pls help me to balance the equation thanksss
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\pmb{\red{\boxed{\sf{Na_{2}O(s)+H_{2}O(l)\dashrightarrow 2NaOH(aq) }}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
Identify each transition in this flowchart as a chemical change or a physical change.
Answer:
so i think physical change
what’s the name of the organic molecule
Answer:
hexane
Explanation:
This is a 6- carbon hydrocarbon with no multiple bonds or any functional groups (such as -OH). Thus, the prefix 'hex' refers to the 6 carbons and 'ane' refers to the molecule being an alkane.
Naming molecules:
Number of carbons
• pentane: 5 carbons
• hexane: 6 carbons
• heptane: 7 carbons
• octane: 8 carbons
• nonane: 9 carbons
Functional groups (for 6- carbons molecules)
• Alkene (C=C): hexene
• Alcohol (-OH): hexanol
• Alkyne (C≡C): hexyne
what apparatus is used to investigate the conductivity of solutions
differentiate between Physical and chemical changes
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
I HOPE THIS WILL HELP YOU IF NOT THEN SORRY HAVE A GREAT DAY:)What is known about a reaction with a positive enthalpy?
Answer:
"Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings of the reaction."
Explanation:
When enthalpy is positive and delta H is greater than zero, this means that a system absorbed heat. This is called an endothermic reaction. When enthalpy is negative and delta H is less than zero, this means that a system released heat. This is called an exothermic reaction.
What does a high positive enthalpy mean?
The sign of q for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is exothermic if heat is released by the system into the surroundings. Because the surroundings are gaining heat from the system, the temperature of the surroundings increases.
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define measurment and its importance
Answer:
Explanation:
A measurement is the action of measuring something, or some amount of stuff. So it is important to measure certain things right, distance, time, and accuracy are all great things to measure. By measuring these things or in other words, by taking these measurements we can better understand the world around us.
Answer:
Measurement is the process of comparison of an unknown physical quantity with a known physical quantity.
It is important because measurement is needed in every day life we need measurement in simply cooking food to designing a house and many more other works.
Explanation:
hope this helps you.
What process is used to refine aluminum from its ore bauxite?
A. Electrolysis
B. Electrolytic oxidation
C. Voltaic cell processing
D. Smelting
The correct option for the process used to refine aluminum from its bauxite ore is option D.
D. Smelting
The reason why smelting is the correct choice is as follows;
Bauxite is the aluminum ore from which alumina, also known as aluminum
oxide, Al₂O₃, is produced. Bauxite is extracted from the topsoil regions of
some subtropical and tropical regions, and the Bayer process is primarily
then used to produce alumina from the bauxite.
Aluminum is produced from the alumina by an aluminum smelting process
known as the Hall—Heroult electrolytic process which involves the use of a
carbon anode and direct current to produce aluminum by reducing the
aluminum oxide
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Describe the principle and process for the manufractured of sulphuric acid witha a well labeled diagram by contact process.
The steps involved in the manufacture of sulphuric acid by contact process:
(1) Sulphur (or iron pyrites) are burnt in air to form sulphur dioxide.
S+O2→SO24FeS2+11O2→2Fe2O3+8SO2
(2) Catalytic oxidation of sulphur dioxide to sulphur trioxide.
2SO2+O2V2O52SO3ΔrHo=−196.6kJ
The reaction is reversible and exothermic.
(3) Sulphur trioxide is dissolved in 98% sulphuric acid to form oleum (fuming sulphuric acid).
SO3+H2SO4→H2S2O7
(4) Oleum is diluted with water to form sulphuric acid of desired concentration.
H2S2O7+H2O→2H2SO4
and
Manufacture of H2SO4 by contact process involves three steps:
1. Burning of sulphur in air to generate SO2.
2. Conversion of SO2 to SO3 by oxidation with air in the presence of
4. Calculate the relative molecular masses of the following substances [RAM: H=1, O=16, S=32, C=12, N=14] a. CH2(NH2)COOH b. H2SO4
Answer:
a. CH2(NH2)COOH
[tex]molecular \: mass = (12 \times 2) + (5 \times 1) + (14 \times 1) + (16 \times 2) \\ = 24 + 5 + 14 + 32 \\ = 75 \: grams[/tex]
b. H2SO4
[tex]molecular \: mass = (2 \times 1) + 32 + (16 \times 4) \\ = 2 + 32 + 64\\ = 98 \: grams[/tex]
HELP . Read the following graduated cylinder.
Use this media to help you complete the question.
22.0 mL
22 mL
23.0 mL
22.5 mL
The volume of the liquid from the graduated cylinder is 22.5 mL
The last option (22.5 mL) is the correct option
The question seems to be incomplete
The image that completes the question is shown in the attachment below.
From the image, we observe that the liquid meniscus is between the 20 mL and 25 mL marks. That means the volume will lie in this range.
NOTE: The meniscus of a liquid is the upward or downward curve seen at the top of a liquid in a container.
The type of curve shown in the image is a concave meniscus and the volume of the liquid is read from the bottom of the curve.
To read the value from the graduated cylinder, we will first determine the difference between two consecutive lines. Between the 20 mL and 25 mL mark (two thick lines), we have 5 spaces separated by thin lines.
The measure between two consecutive lines is the difference between two thick lines divided by number of spaces between them
∴ The measure between two consecutive lines = (25mL - 20mL) ÷ 5
The measure between two consecutive lines = 5mL ÷ 5 = 1 mL
Now, to read the position of the liquid,
Starting from the 20 mL mark, the liquid exceeds two more lines + half way to the next line ( that is 2mL + 0.5 mL)
∴ The position of the liquid is 20 mL + 2mL + 0.5 mL = 22.5 mL
Hence, the volume of the liquid from the graduated cylinder is 22.5 mL
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Answer:
The answer is 22.5 mL
Explanation:
I hope this helps you :)
