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3 years ago

REALLY NEED HELP WITH THESE CHEM QUESTIONS!! IF GOOD AT CHEM PLEASE HELP WILL GIVE BRAINLIEST AND WORTH 30 POINTS!

Chemistry

1 answer:

astraxan [27]3 years ago

6 0

The missing isotope in the equation is going to have the atomic mass and atomic number as the difference between the numbers of the other isotopes mass and atomic number respectively.
atomic mass 210-206= 4
atomic number 84-82= 2
the symbol has to correspond to the element with the atomic number. In this case 2 = He

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What type of chemical reaction is:

Valentin [98]

Answer:

Synthesis

Explanation:

That's the answer to that question

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3 years ago

Read 2 more answers

In a single replacement reaction, the chloride ion in NaCl can be replaced

MakcuM [25]

Answer:

c. fluorine

Explanation:

A single replacement reaction is defined as the chemical reaction in which a strong molecule replaces the weak molecule from a compound.

In a single replacement reaction, the chloride ion in NaCl can be replaced by fluorine and gives Sodium fluoride as fluorine (F) is stronger than chlorine (Cl) and from other given molecules also. So the single replacement reaction between NaCl and F will be:

NaCl + F2 => NaF + Cl2

Hence, the correct answer is "c. fluorine".

4 0

3 years ago

A 2.50-l flask contains a mixture of methane (ch4) and propane (c3h8) at a pressure of 1.45 atm and 20°c. when this gas mixture

Cerrena [4.2K]

Answer:- Mole fraction of methane in the original gas mixture is 0.854.

Solution:- From given volume, pressure and temperature, we could calculate the total moles of the gaseous mixture of methane and propane using ideal gas law as:

PV = nRT

$n=\frac{PV}{RT}$

V = 2.50 L

P = 1.45 atm

T = 20 + 273 = 293 K

Let's plug in the values in the equation:

$n=(\frac{1.45*2.50}{0.0821*293})$

n = 0.151

Let's say the solution has X moles of methane. Then moles of propane would be = (0.151 - X)

The combustion equations of methane and propane are:

$CH_4+2O_2\rightarrow CO_2+2H_2O$

$C_3H_8+5O_2\rightarrow 3CO_2+4H_2O$

From methane balanced equation, there is 1:1 mol ratio between methane and carbon dioxide. So, X moles of methane would produce X moles of carbon dioxide.

From balanced equation of propane, there is 1:3 mol ratio between propane and carbon dioxide. So, (0.151 - X) moles of propane would give 3(0.151 - X) moles of carbon dioxide.

So, total moles of carbon dioxide that we would get from methane and propane combustion are:

X + 3(0.151 - X)

From given data, 8.60 g of carbon dioxide are formed by the combustion of gas mixture.

moles of Carbon dioxide = $8.60g(\frac{1mol}{44g})$

moles of carbon dioxide = 0.195 mol

Hence, 0.195 = X + 3(0.151 - X)

Let's solve this for X as:

0.195 = X + 0.453 - 3X

0.195 = 0.453 - 2X

2X = 0.453 - 0.195

2X = 0.258

$X=\frac{0.258}{2}$

X = 0.129

So, there are 0.129 moles of methane in the mixture.

moles of propane = 0.151 - 0.129 = 0.022

mole fraction of methane = $\frac{moles of Methane}{total moles}$

mole fraction of methane = $\frac{0.129}{0.151}$

mole fraction of methane = 0.854

Hence, the mole fraction of methane gas in the original gas mixture is 0.854.

6 0

3 years ago

Which analogy can best be likened to the activation energy of a chemical reaction?

olganol [36]

The activation energy of a reaction is the minimum energy that must be overcome in order for the reaction to take place. One way of reaching the activation energy is by manipulating the process conditions like pressure or temperature. But the most common method is by adding an enzyme. An enzyme speeds up the rate of the reaction but does not actively take part in it.

An analogy would be pushing heavy wooden block down a slope. No matter how many people push on it, the block won't move because of friction. But if you spill oil on the floor, the block would effortlessly move down the slope. The oil here is like an enzyme in a reaction.

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4 years ago

Jenna took an open bowl of leftover mashed potatoes from the refrigerator. She determined that chemical changes occurred since t

Kamila [148]

Answer:

maybe the potatoes took a different form? They smell different, look different taste different, etc.

Explanation:

5 0

3 years ago