i don’t understand this lolz help

Answer:

Stinging cell, nematocysts.

Explanation:

Corals have tentacles present near the oral opening. The tentacles comprise cells called stinging cells. These cells contain nematocysts used by corals to sting the prey and stun them using the tentacles. These stinging cells present near the mouth which contains nematocysts that is an organelle that produces toxic substances used by the coral to catch their prey.

Answer:

0.7 moles of Ag are produced

Explanation:

Given data:

Mass of silver carbonate = 97.4 g

Moles of silver produced = ?

Solution:

Chemical equation:

2Ag₂CO₃     →     4Ag + 3CO₂

Number of moles of Ag₂CO₃ :

Number of moles = mass/molar mass

Number of moles = 97.4 g/ 275.75 g/mol

Number of moles = 0.35 mol

Now we will compare the moles of Ag and Ag₂CO₃.

              Ag₂CO₃           :         Ag

                    2                :           4

                0.35              :             4/2×0.35 = 0.7

0.7 moles of Ag are produced.

Explanation:

The tendency of metals to lose electrons is a measure of their electropositivity or metallicity.

Electropositivity is a measure of the tendency of atoms of an element to lose electrons. It is closely related to ionization energy and electronegativity of an element.

Answer:

95.7 cal

Explanation:

The heat required can be calculated as follows:

heat = m x Cp x ΔT

Where:

m = mass of iron = 87 g

Cp = specific heat of iron = 0.110 cal/g.°C

ΔT = change in temperature = final T - initial T = 40°C - 30°C = 10°C

Thus, we introduce the data in the mathematical equation to calculate the heat in calories:

heat = 87 g x 0.110 cal/g.°C x 10°C = 95.7 cal

Answer:

Mass = 0.44 g

Explanation:

Given data:

Mass of vanadium =  ?

Number of atoms of vanadium = 5.2 × 10²¹ atoms

Solution:

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

5.2 × 10²¹ atoms ×  1mol / 6.022 × 10²³ atoms

0.86× 10⁻²  mol

0.0086 mol

Mass of vanadium:

Mass =  number of moles × molar mass

Mass = 0.0086 mol × 50.9 g/mol

Mass = 0.44 g

Explanation:

Interionic Attractions are when an ion is surrounded by an ionic atmosphere which has a net charge opposite for its own. ... The ionic atmosphere cannot created nor destroyed. In solutions with weak electrolytes the number of ions is not large, therefore the effect of the interionic attraction is small.

Answer:

The periodic table of elements puts all the known elements into groups with similar properties. This makes it an important tool for chemists, nanotechnologists, and other scientists. If you get to understand the periodic table and learn to use it, you'll be able to predict how chemicals will behave.

Answer:

Okayy

Explanation:

The periodic table arranges the chemical elements

All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods

It have many properties. Each column is called a group.

ALSO Metals are placed on the left-hand side of the periodic table , and non-metals on the right.

Metalloids can also be called semimetals. On the periodic table, the elements colored yellow, which generally border the stair-step line, are considered to be metalloids.

Explanation:

Both cohesion and molecular interchange contribute to liquid viscosity. The impact of increasing the temperature of a liquid is to reduce the cohesive forces while simultaneously increasing the rate of molecular interchange. The former effect causes a decrease in the shear stress while the latter causes it to increase.

temperature?

The viscosity of liquids decreases rapidly with an increase in temperature, and the viscosity of gases increases with an increase in temperature. Thus, upon heating, liquids flow more easily, whereas gases flow more sluggishly.

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Answer:

2000 millimoles of AlCl₃

Explanation:

From the question given above, the following data were obtained:

Volume of solution = 1.8 L

Molarity of solution = 1.1 mol /L

Millmole of AlCl₃ =?

Next, we shall determine the number of mole of AlCl₃ in the solution.

This can be obtained as follow:

Volume of solution = 1.8 L

Molarity of AlCl₃ solution = 1.1 mol /L

Number of mole of AlCl₃ =?

Molarity = mole /Volume

1.1 = Number of mole of AlCl₃ / 1.8

Cross multiply

Number of mole of AlCl₃ = 1.1 × 1.8

Number of mole of AlCl₃ = 1.98 moles

Finally, we shall convert 1.98 moles to millimoles. This can be obtained as follow:

1 mole = 1000 millimoles

Therefore,

1.98 mole = 1.98 mole × 1000 millimoles / 1 mole

1.98 mole = 1980 millimoles

1.98 mole ≈ 2000 millimoles

Thus, the chemist added 2000 millimoles of AlCl₃

Answer:

60

Explanation:

The formula of the compound is given as:

              HC₂H₃O₂

To find the formula mass we sum up the atomic masses of the component elements;

  Atomic mass:

         H  = 1

         C  = 12

         O = 16

 HC₂H₃O₂  = 1 + 2(12) + 3(1) + 2(16)

                   = 1 + 24 + 3 + 32

                   = 60

Answer: The ratio of number of hydroxide ions to iodide ions is 2 : 1.

Explanation:

The chemical equation for the oxidation of iodide ion is oxidized to hypoiodite ion by permanganate follows:

[tex]2MnO_4^-+I^-+H_2O\rightarrow 2MnO_2(s)+IO_3^{-}+2OH^{-}[/tex]

According to mole concept:

1 mole of a substance contains [tex]6.022\times 10^{23}[/tex] number of particles

Moles of iodide ions = 1 mole

Number of iodide ions = [tex](1\times 6.022\times 10^{23}[/tex]

Moles of hydroxide ions = 2 mole

Number of hydroxide ions = [tex](2\times 6.022\times 10^{23}[/tex]

Taking the ratio of number of hydroxide ions and number of iodide ions are as follows:

[tex]\frac{\text{Number of hydroxide ions}}{\text{Number of iodide ions}}=\frac{(2\times 6.022\times 10^{23})}{(1\times 6.022\times 10^{23})}\\\\\frac{\text{Number of hydroxide ions}}{\text{Number of iodide ions}}=\frac{2}{1}[/tex]

Hence, the ratio of number of hydroxide ions to iodide ions is 2 : 1.

Answer:

Amount (Mole) of carbon = 0.008303 mole

Mass (gramm)of Carbon = 0.0997 g.

Explanation:

From Avogadro's law, we know that 1 mole of carbon contains 6.022×10²³ atoms.

Then the mole of carbon that contains 5.0×10²¹ atoms can be computed as (5.0×10²¹ / 6.022×10²³)

=0.008303 mole

5.0×10²¹ atoms is contained in 0.008303 mole

Hence, Amount (Mole) of carbon = 0.008303 mole

the mass of carbon can be computed , we know that

Mole = mass /Molar mass

Where Molar mass of carbon = 12.01 g/mol

n=0.008303 mol

Making " mass" subject of the formula,

mass=Mole ,× Molar mass

=0.008303 x 12.01

= 0.0997 g.

Answer:

air

Explanation:

Vocal folds vibrate when excited by aerodynamic phenomena; they are not plucked like a guitar string. Air pressure from the lungs controls the open phase. The passing air column creates a trailing “Bernoulli effect,” which controls the close phase.

Answer:

Her speed is 1.1 m/s, and her velocity is 0 m/s.

Explanation:

Hello!

In this case, since the speed is the defined as the distance traveled over the elapsed time:

[tex]s=\frac{d}{t}[/tex]

And the velocity is defined as the change in displacement over the time interval:

[tex]v=\frac{\Delta d}{\Delta t}[/tex]

Thus, since the total distance traveled was 400 m and the total time 6 mins (360 s), we compute the speed as:

[tex]s=\frac{400m}{360s}=1.1m/s[/tex]

And the velocity is 0 m/s because the initial point is the very same final point as the track was circular. Therefore the answer is Her speed is 1.1 m/s, and her velocity is 0 m/s.

Best regards!

When a liquid changes into a solid, it is called solidification. When a gas changes into a solid, it is called deposition . When a liquid changes into gas, it is called evaporation. Phase changes are usually caused by changes in temperature or pressure.

Answer: 1.8 moles Fe and 2.7 moles [tex]CO_2[/tex] are produced.

Explanation:

The balanced chemical reaction is:

[tex]Fe_2O_3+3CO\rightarrow 2Fe+3CO_2[/tex]  

According to stoichiometry :

3 moles of [tex]CO[/tex] require 1 mole of [tex]Fe_2O_3[/tex]

Thus 2.7 moles of [tex]CO[/tex] will require=[tex]\frac{1}{3}\times 2.7=0.9moles[/tex]  of [tex]Fe_2O_3[/tex]

Thus [tex]CO[/tex] is the limiting reagent as it limits the formation of product and [tex]Fe_2O_3[/tex] is the excess reagent.

As 3 moles of [tex]CO[/tex] give = 2 moles of [tex]Fe[/tex]  and 3 moles of [tex]CO_2[/tex]

Thus 2.7 moles of [tex]CO[/tex] will give =[tex]\frac{2}{3}\times 2.7=1.8moles[/tex]  of [tex]Fe[/tex]  and [tex]\frac{3}{3}\times 2.7=2.7moles[/tex]  of [tex]CO_2[/tex]

Thus 1.8 moles Fe and 2.7 moles [tex]CO_2[/tex] are produced.

Answer:

dissociation, in chemistry, separation of a substance into atoms or ions. ... For example, hydrogen molecules (H2) dissociate into atoms (H) at very high temperatures; at 5,000°K about 95% of the molecules in a sample of hydrogen are dissociated into atoms.

Explanation:

Answer:

yeesss. I am sooooo ssaaaddddd

Answer:

Yes and her last word was meat

Explanation:

Sasha supremacy

Answer:

Exothermic

Explanation:

We as humans do not absorb heat. A good way to think about it is that when we workout we use energy from our body which causes our body temperature to rise. The energy used from food maintains our blood, respiration, and other systems in optimal condition. This requires energy from our body which ends up leaving the body as heat.

Answer:

Answers with detail are given below.

Explanation:

C₆H₁₂O₆   →   2C₂H₅OH  + 2CO₂

Anaerobic respiration in plants produced ethanol which if accumulate then cause the harmful effect in plants. It is also occur in some microorganisms such as yeast.

C₆H₁₂O₆    →   2C₃H₆O₃

Anaerobic respiration in animals pyruvate converted into lactic acid and it is not as harmful as ethanol in plant if accumulate. It is produced during exercise. It can produce the cramps which can be cured with massage.

C₆H₁₂ + O₂       →       CO₂ + H₂O

This reaction is the combustion reaction of cyclohexane. Cyclohexane burnt in the presence of oxygen and form water and carbon dioxide.

Answer:

D. The model can be observed from the classroom more easily

Explanation:

From the concept of using wire coil to model and the concept of using spring coil to measure, we can come to the conclusion that the correct answer is Option D.

Answer:

It is always twice the value of the actual yield.

Explanation:

Answer:

C

cell wall only in plants

chloroplast only in plants

enlarged vacuoles only in plants

cell membrane in both

hope this helps :)

Explanation:

Answer:

a. cell wall b. membrane

Answer:

a) 15.3 mol O₂

b) 10.2 mol CO₂; 13.6 mol H₂O

Explanation:

Step 1: Write the balanced equation

2 C₃H₇OH + 9 O₂ ⇒ 6 CO₂ + 8 H₂O

Step 2: Calculate the moles of O₂ that react with 3.40 moles of C₃H₇OH

The molar ratio of C₃H₇OH to O₂ is 2:9. The moles of O₂ required are 9/2 × 3.40 mol = 15.3 mol

Step 3: Calculate the moles of CO₂ produced from 3.40 moles of C₃H₇OH

The molar ratio of C₃H₇OH to CO₂ is 2:6. The moles of CO₂ produced are 6/2 × 3.40 mol = 10.2 mol

Step 4: Calculate the moles of H₂O produced from 3.40 moles of C₃H₇OH

The molar ratio of C₃H₇OH to H₂O is 2:8. The moles of H₂O produced are 8/2 × 3.40 mol = 13.6 mol

Answer:

OH⁻(aq) + H⁺(aq) ⇒ H₂O(l)

Explanation:

Let's consider the molecular equation that occurs when aqueous solutions of lithium hydroxide and hydrobromic acid undergo a neutralization reaction.

LiOH(aq) + HBr(aq) ⇒ LiBr(aq) + H₂O(l)

The complete ionic equation includes all the ions and the molecular species.

Li⁺(aq) + OH⁻(aq) + H⁺(aq) + Br⁻(aq) ⇒ Li⁺(aq) + Br⁻(aq) + H₂O(l)

The net ionic equation includes only the ions that participate in the reaction and the molecular species.

OH⁻(aq) + H⁺(aq) ⇒ H₂O(l)

Answer:

48g

Explanation:

2Hg(l) + O₂(g) => 2HgO

44g      excess        ?

44g/200.59g·mol⁻¹ = 0.219 mole Hg(l) = 0.219 mole HgO(s) produced.*

*Since coefficients are equal for Hg and HgO then the moles of HgO produced is the same as moles Hg used.

Convert 0.219 mole HgO to grams => 0.219mol x 216.95g/mol = 47.512g HgO ≅ 48g (2 sig figs)

To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. The correct option is option C.

Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.

The other characteristic of balanced reaction is that physical state should be written with each compound or molecule on reactant and product side. Physical state should be written in brackets. s means solid, l means liquid, g means gas.

2Hg(l) + O₂(g) [tex]\rightarrow[/tex] 2HgO

44g      excess        ?

The mole ratio between Hg and HgO is 1:1.

44g÷200.59g/mol= 0.219 mole of Hg= 0.219 mole of HgO

mass of HgO=0.219mol x 216.95g/mol

                     = 47.512g

Therefore, the correct option is option C.

Learn more about the balanced equation, here:

https://brainly.com/question/7181548

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Answer:

CH₂

Explanation:

Given parameters:

Percentage composition:

          Carbon  = 40.1%

          Hydrogen  = 6.6%

Unknown:

Empirical formula of the compound  = ?

Solution:

The empirical formula of a substance is its simplest formula.

 Elements                             Carbon                             Hydrogen

Percentage

Composition                           40.1                                     6.6

Molecular mass                        12                                         1

Number of moles                  40.1/12                                  6.6/1

                                                3.342                                    6.6

Divide through by

the smallest                         3.342/3.342                           6.6/3.342

                                                      1                                        2

So the empirical formula of the compound is CH₂