A higher concentration of molecules causes a faster chemical reaction this is known as

If 45.0 mL of ethanol (density =0.789g/mol) initially at 6.0°C mix with 45.0 mL of water (density =1.0 g/mol) initially at 28.0°

Likurg_2 [28]

The final temperature of the mixture : 21.1° C

<h3>Further explanation </h3>

The law of conservation of energy can be applied to heat changes, i.e. the heat received / absorbed is the same as the heat released

Q in(gained) = Q out(lost)

Heat can be calculated using the formula:

Q = mc∆T

Q = heat, J

m = mass, g

c = specific heat, joules / g ° C

∆T = temperature difference, ° C / K

Q ethanol=Q water

mass ethanol=

$\tt mass=\rho\times V\\\\mass=0.789\times 45=35.505~g$

mass water =

$\tt mass=1~g/ml\times 45~ml=45~g$

then the heat transfer :

$\tt 35.505\times 2.42~J/g^oC\times (t-6)=45\times 4.18~J/g^oC\times (28-t)\\\\85.922t-515.533=5266.8-188.1t\\\\274.022t=5782.33\rightarrow t=21.1^oC$

5 0

3 years ago

A compound contains 72% magnesium and 28% nitrogen. What is its empirical formula?

SashulF [63]

So the empirical formula is Mg3N2

7 0

3 years ago

An ionic bond forms when atoms blank electrons

8_murik_8 [283]

Answer:

An ionic bond forms when atoms transfer electrons.

Explanation:

Ionic bonds are formed when atoms transfer electrons. (In contrast, covalent bonds are formed when atoms share electrons.)

There's a distinction between the two: when two atoms react to form an ionic bond, one atom would completely lose one electron, while the other would completely gain that electron. The atom that loses the electron becomes a positively-charged ion called a cation, whereas the atom that gains the electron becomes a negatively-charged ion called an anion.

For example, consider the reaction between a sodium $\rm Na$ atom and a chlorine $\rm Cl$ atom: $\rm Na + Cl \to NaCl$ .

When the sodium atom and the chlorine atom encounter, the sodium atom would lose one electron to form a positively-charged sodium ion, $\rm Na^{+}$ . The chlorine atom would gain that electron to form a negatively-charged chlorine ion $\rm Cl^{-}$ .

These two ions will readily attract each other because of the opposite electrostatic charges on them. This electrostatic attraction (between two ions of opposite charges) is an ionic bond.

Overall, it would appear as if the sodium $\rm Na$ atom transferred an electron to the chlorine $\rm Cl$ atom to form an ionic bond.

In contrast, when two atoms react to form a covalent bond, they share electrons without giving any away completely. Therefore, it is possible to break certain covalent bonds apart (using a beam of laser, for example) and obtain neutral atoms.

On the other hand, when an ionic bond was broken, the result would be two charged ions- not necessarily two neutral atoms. The electron transfer could not be reversed by simply breaking the bond.

For example, when table salt $\rm NaCl$ is melted (at a very high temperature,) the ionic bond between the sodium ions and chloride ions would (mostly) be broken. However, doing so would only generate a mixture of $\rm Na^{+}$ and $\rm Cl^{-}$ ions- not sodium and chlorine atoms.

7 0

2 years ago

Which of the following has the lowest entropy?

Valentin [98]

I believe that the answer is B: H2O(s) because is the makeup of water also known as one hydrogen and two oxygen. So water as more entropy and the s stands for sol fore i think wich means it contains the most entropy.

5 0

3 years ago

Read 2 more answers

A potassium bromide solution is 8.30% potassium bromide by mass and its density is 1.03 g/ml. what mass of potassium bromide is

pshichka [43]

<u>Answer:</u> The mass of potassium bromide present in 41.2 mL of solution will be 3.522 grams.

<u>Explanation:</u>

We are given that KBr is present in 8.3% KBr solution, which means that 8.3 grams of potassium bromide is present in 100 gram of the solution.

To calculate the volume of KBr, we use the formula:

$Density=\frac{Mass}{Volume}$

Mass of the solution = 100 grams

Density of KBr solution = 1.03g/mL

Volume of the solution = ? mL

Putting values in above equation, we get:

$1.03g/mL=\frac{100g}{Volume}\\\\Volume=97.08mL$

Now, to calculate the mass of KBr in 41.2mL of the solution, we use unitary method.

In 97.08 mL of solution, mass of KBr present is 8.3 grams.

So, 41.2 mL of solution will contain = $\frac{8.3g}{97.08mL}\times 41.2mL=3.522g$ of KBr.

Hence, the mass of potassium bromide present in 41.2 mL of solution will be 3.522 grams.

7 0

3 years ago