Which one is convection??? A heater in a fish tank warming the water at the bottom of the tank, Batteries in a flashlight converting chemical energy into light, Touching a stove and burning your hand, or Warming up next to a fire on a cold night

Answer:Solar flares have been known to affect electronic communication because their energy stirs up the Earth's upper atmosphere.

Explanation:

Answer:

ΔH = -29.78 KJ/mol

Explanation:

To calculate the Standard enthalpy of change for this reaction, we need to use the following expression:

ΔH = ΔHf(products) - ΔHf(reactants)   (1)

Now, the standard heat of formation can be found in different handbooks or websites. I manage to find these for the compounds of the reaction:

ΔHf Ca(OH)₂ = -1002.82 KJ/mol

ΔHf HCl = -167.4 KJ/mol

ΔHf CaCl₂ = -795.8 KJ/mol

ΔHf  H₂O = -285.8 KJ/mol

With these values, we can calculate the enthalpy change of the reaction using (1). Let's calculate first the individual values of the products and reactants and then, we can use (1):

Reaction: Ca(OH)₂ + 2HCl ---------> CaCl₂ + 2H₂O

ΔHf (products) = ΔHf CaCl₂ + ΔHf H₂O

ΔHf (products) = (-795.8) + 2(-285.8)

ΔHf (products) = -1367.4 KJ/mol

Keep in mind that if the compound has a coefficient that balances the reaction, you need to multiply that number by the standard heat. Let's calculate reactants:

ΔHf (reactants) = ΔHf Ca(OH)₂ + ΔHf HCl

ΔHf (reactants) = (-1002.82) + 2(-167.4)

ΔHf (reactants) = -1337.62 KJ/mol

Finally using expression (1) we have:

ΔH = (-1367.4) - (-1337.22)

Answer:

heterozygous

The balanced equation :

4Fe + 3O₂⇒ 2Fe₂O₃

Given

Rust reaction

Required

Balanced equation

Solution

Reaction

Fe + O₂⇒ 2Fe₂O₃

For a simple equation where one of the reaction coefficients is known, we can immediately add the corresponding coefficient using the principle that the number of atoms of the components in the reactants and products is the same.

In the above reaction :

Fe, left=1, right = 4, so coefficient in the left=4

O, left=2, right = 6, so coefficient in the left=3

Answer:

The most reactive metal elements is Group 1.

Answer:

502.9 nm

Explanation:

Energy to break to the bond of carbon-iodine is not given assuming it to be 238KJ/mol

we know that

ΔE= hυ

also, υ= c/λ

therefore λ = hc/ΔE

[tex]= \frac{6.626\times10^{-34}\times3\times10^8}{238\times10^3}\\=0.08352\times10^{-29} m mol[/tex]

also, 1 mol = 6.022×10^23 atoms or molecules

[tex]\lambda= 0..08352\times10^{-29}\times6.022\times10^{23}\\=502.9 \times10^{-9}m\\=502.9 nm[/tex]

Answer: When water is added to vinegar, the vinegar's acidity decreases, which results in a higher number on the pH scale. However, diluting vinegar with water can never make it alkaline, because water itself is not alkaline; the pH of the mixture can't be higher than the higher pH value of the two components.

Explanation: it loses acidity. Diluting it can never make it alkaline and the PH mixture can’t be higher.

Answer:

There are 4 oxygen and 1 sulfur.

Explanation:

Calcium sulfate is made up of 1 calcium, 1 sulfur and 4 oxygen.

Answer:

No

Explanation:

It is not easier for an atom to lose a proton or a neutron because these particles are held together by very strong nuclear forces within the atom.

Protons are positively charged particles

Neutrons do not carry any charges.

  In the nucleus of an atom, both protons and neutrons can be found.

As with both particles, the very strong attractive force makes them very difficult to remove in ordinary chemical reactions.

Nuclear forces are one of the strongest forces that keeps an atom especially the nucleus together. Only in nuclear reactions to we encounter a situation where nuclear materials are changed, in that regard the properties of the atom also changes.

Answer:

compressible.

definite volume.

low density.

indefinite shape.

Answer:

0.4 m/s2 towards the West.

Explanation:

MARK ME THE BRAINLIES PLEASE!!

Answer:

d = 1.91 g/cm³

d = 1.91 g/mL

Explanation:

Given data:

Mass of cheese = 67 g

Volume of cheese = 35 cm³

Density of cheese = ?

Solution:

Formula:

d = m/v

by putting values,

d = 67 g/ 35 cm³

d = 1.91 g/cm³

1cm³ = 1mL

d = 1.91 g/mL

Relative humidity is the percentage of what it can hold. Humidity is the measure of the amount of water vapor it can hold.

hope this helps ^^

Answer:

Group 1 elements tend to react with group Group 17 elements to form alkyl halide.

Answer:

A higher hill will give more potential energy, and a lower hill will give less.

Explanation: Gravitational potential energy is the energy stored in an object based on its height and mass.  The potential energy in an object increases as its elevation increases.

Answer:

[tex]r=-0.033\frac{M}{s}[/tex]

Explanation:

Hello!

In this case, since the average rate of reaction is computed as a change given by:

[tex]r=\frac{\Delta [NH_4NO_2 ]}{\Delta t}[/tex]

In such a way, given the concentrations at the specified times, we plug them in to obtain:

[tex]r=\frac{(1.48M-4.12M)}{(330s-250s)}\\\\r=-0.033\frac{M}{s}[/tex]

Whose negative sign means the concentration decreased due to the decomposition.

Best regards!

Answer:

0.288g KBT can be dissolved

Explanation:

The dissolution of KBT produce the dissociation in K⁺ and BT⁻ ions as follows:

KBT(s) → K+(aq) + BT-(aq) Ksp = 3.8×10-4

Where Ksp is defined as:

Ksp = 3.8x10⁻⁴ = [K⁺][BT⁻]

Thus, we need to find the concentration of KBT that can be dissolved = [K⁺] = [BT⁻]:

3.8x10⁻⁴ = [K⁺][BT⁻]

3.8x10⁻⁴ = [KBT][KBT]

3.8x10⁻⁴ = [KBT]²

0.01949M = [KBT]

In 280mL = 0.280L, the moles of KBT that can be dissolved are:

0.01949mol / L * 0.280L =

5.458x10⁻³ moles of KBT. In grams (Using molar mass):

5.458x10⁻³ moles of KBT * (188.2g/mol) =

Answer:

Explanation:

The chemical formula for hydrogen phosphate​ is HPO₄²⁻

Answer:

Potential energy = mass(velocity)

Explanation:

It is the formula used to explain how to find the answer for potential energy

Answer:

X¹/⁴ Y¹/²

Explanation:

From the question given above, we are required to simplify:

⁸√(X²Y⁴)

The above expression can be simplified as follow:

⁸√(X²Y⁴)

Recall:

ⁿ√Aᵐ = Aᵐ/ⁿ

Therefore,

⁸√(X²Y⁴) = X²/⁸ Y⁴/⁸

⁸√(X²Y⁴) = X¹/⁴ Y¹/²

Thus, ⁸√(X²Y⁴) is equivalent to X¹/⁴ Y¹/²

collision theory

Explanation:

Collision theory, theory used to predict the rates of chemical reactions, particularly for gases. The collision theory is based on the assumption that for a reaction to occur it is necessary for the reacting species (atoms or molecules) to come together or collide with one another.

Answer: b

Explanation:

Answer:

im pretty sure 18 is eye

Explanation:

Answer:

6.07 g.

Explanation:

Hello!

In this case, given the chemical reaction:

[tex]Zn + H_2CO_3 \rightarrow ZnCO_3 + H_2[/tex]

We first need to compute the moles of each reactant considering their molar masses:

[tex]n_{Zn}=4gZn*\frac{1molZn}{65.38 gZn} =0.0612molZn\\\\n_{H_2CO_3}=3gH_2CO_3*\frac{1molH_2CO_3}{62.03 gH_2CO_3} =0.0484molH_2CO_3[/tex]

Now, compute the mass of zinc carbonate yielded by each reactant in order to pick out the correct limiting reactant:

[tex]n_{ZnCO3}^{by\ Zn} = 0.0612molZn*\frac{1molZnCO3}{1molZn}*\frac{125.4 gZnCO3}{1molZnCO3}=7.67gZnCO3 \\\\n_{ZnCO3}^{by\ H_2CO3} = 0.0484molH_2CO3*\frac{1molZnCO3}{1molH_2CO3}*\frac{125.4 gZnCO3}{1molZnCO3}=6.07gZnCO3[/tex]

Thus, we conclude carbonic acid is the limiting reactant as it produces the fewest grams of product and therefore the yielded mass of zinc carbonate product 6.07 g.

Best regards.

Answer:

Density

Explanation:

Density is defined as the mass per unit volume. It is the ratio between the mass and the volume of a substance. It does not matter how large or small a sample of matter is, the same substance will always have the same density, because of this. The ratio between the mass and volume remains the same.