On Wednesday a girl asked me out what do i say?

What is the percent composition by mass of sulfur in the compound mgso4

Margaret [11]

Answer:

26.7% is the percent composition by mass of sulfur in a compound named magnesium sulfate.

Explanation:

Molar mass of compound = 120 g/mol

Number of sulfur atom = 1

Atomic mass of sulfur = 32 g/mol

Percentage of element in compound :

$=\frac{\text{Number of atoms}\times \text{Atomic mass}}{\text{molar mas of compound}}\times 100$

Sulfur :

$=\frac{1\times 32 g/mol}{120 g/mol}\times 100=26.7\%$

26.7% is the percent composition by mass of sulfur in a compound named magnesium sulfate.

6 0

3 years ago

Solid NaBr is slowly added to a solution that is 0.073 M in Cu+ and 0.073 M in Ag+.Which compound will begin to precipitate firs

saul85 [17]

Answer :

AgBr should precipitate first.

The concentration of $Ag^+$ when CuBr just begins to precipitate is, $1.34\times 10^{-6}M$

Percent of $Ag^+$ remains is, 0.0018 %

Explanation :

$K_{sp}$ for CuBr is $4.2\times 10^{-8}$

$K_{sp}$ for AgBr is $7.7\times 10^{-13}$

As we know that these two salts would both dissociate in the same way. So, we can say that as the Ksp value of AgBr has a smaller than CuBr then AgBr should precipitate first.

Now we have to calculate the concentration of bromide ion.

The solubility equilibrium reaction will be:

$CuBr\rightleftharpoons Cu^++Br^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Cu^+][Br^-]$

$4.2\times 10^{-8}=0.073\times [Br^-]$

$[Br^-]=5.75\times 10^{-7}M$

Now we have to calculate the concentration of silver ion.

The solubility equilibrium reaction will be:

$AgBr\rightleftharpoons Ag^++Br^-$

The expression for solubility constant for this reaction will be,

$K_{sp}=[Ag^+][Br^-]$

$7.7\times 10^{-13}=[Ag^+]\times 5.75\times 10^{-7}M$

$[Ag^+]=1.34\times 10^{-6}M$

Now we have to calculate the percent of $Ag^+$ remains in solution at this point.

Percent of $Ag^+$ remains = $\frac{1.34\times 10^{-6}}{0.073}\times 100$

Percent of $Ag^+$ remains = 0.0018 %

3 0

3 years ago

Do you think precipitation has a greater impact on the rate of chemical weathering or mechanical weathering? Explain

nexus9112 [7]

Greater rainfall has an greater increase on the rate of chemical weathering. Rain is a form of precipitation.

6 0

2 years ago

Using the solubility graph place the substances in order from most soluble (#1) to least soluble at 40°C. KNO3, NaClO3,KBr, NaCl

mestny [16]

Answer:

NaClO₃ > KBr > KNO₃ > NaCl.

Explanation:

The attached file contains the graph with the solubility curves for the four substances, KNO₃, NaClO₃, KBr, NaCl.

To determine the solubility of each salt at a certain temperature, you read the temperature on the horizontal axis, labeled Temperature (ºC), and move upward up to intersecting the curve of the corresponding salt. Then, move horizontally up to insersceting the vertical axis, labeled Solubility (g/100g of H₂O), to read the solubility.

The higher the reading on the vertical axis, the higher the solubility.

The red vertical line that I added is at a temperature of 40ºC.

The number in blue indicate the order in which the solubility curves are intersected at that temperature: