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3 years ago

What information can be learned from bloodstains at a crime scene?

Chemistry

1 answer:

tangare [24]3 years ago

3 0

you can learn who's blood it is, you can also see the blood patterns and how the crime maybe happened.

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Why is melting point considered a physical property

miskamm [114]

Answer:

Because you can physically see the object melting when it comes to the melting point. The objects texture, color, temperature, shape, and state of matter (solid, liquid, gas) are possibly changing.

6 0

3 years ago

A student prepares a 1.8 M aqueous solution of 4-chlorobutanoic acid (C2H CICO,H. Calculate the fraction of 4-chlorobutanoic aci

Kruka [31]

Answer:

Percentage dissociated = 0.41%

Explanation:

The chemical equation for the reaction is:

$C_3H_6ClCO_2H_{(aq)} \to C_3H_6ClCO_2^-_{(aq)}+ H^+_{(aq)}$

The ICE table is then shown as:

$C_3H_6ClCO_2H_{(aq)} \ \ \ \ \to \ \ \ \ C_3H_6ClCO_2^-_{(aq)} \ \ + \ \ \ \ H^+_{(aq)}$

Initial (M) 1.8 0 0

Change (M) - x + x + x

Equilibrium (M) (1.8 -x) x x

$K_a = \frac{[C_3H_6ClCO^-_2][H^+]}{[C_3H_6ClCO_2H]}$

where ;

$K_a = 3.02*10^{-5}$

$3.02*10^{-5} = \frac{(x)(x)}{(1.8-x)}$

Since the value for $K_a$ is infinitesimally small; then 1.8 - x ≅ 1.8

Then;

$3.02*10^{-5} *(1.8) = {(x)(x)}$

$5.436*10^{-5}= {(x^2)$

$x = \sqrt{5.436*10^{-5}}$

$x = 0.0073729 \\ \\ x = 7.3729*10^{-3} \ M$

Dissociated form of 4-chlorobutanoic acid = $C_3H_6ClCO_2^- = x= 7.3729*10^{-3} \ M$

Percentage dissociated = $\frac{C_3H_6ClCO^-_2}{C_3H_6ClCO_2H} *100$

Percentage dissociated = $\frac{7.3729*10^{-3}}{1.8 }*100$

Percentage dissociated = 0.4096

Percentage dissociated = 0.41% (to two significant digits)

3 0

3 years ago

Read 2 more answers

What is the molarity of a solution in which 7.1 g of sodium sulfate is dissolved in enough water to make 100. mL of solution?

Sidana [21]

Answer:

0.50 M

Explanation:

Given data

Mass of sodium sulfate (solute): 7.1 g

Volume of solution: 100 mL

Step 1: Calculate the moles of the solute

The molar mass of sodium sulfate is 142.04 g/mol. The moles corresponding to 7.1 grams of sodium sulfate are:

$7.1g \times \frac{1mol}{142.02g} = 0.050mol$

Step 2: Convert the volume of solution to liters

We will use the relation 1 L = 1000 mL.

$100mL \times \frac{1L}{1000mL} =0.100L$

Step 3: Calculate the molarity of the solution

$M = \frac{moles\ of\ solute }{liters\ of\ solution} = \frac{0.050mol}{0.100L} =0.50 M$

3 0

3 years ago

Read 2 more answers

A solution was found to have a 15.6 % transmittance at 500 nm, its wavelength of maximum absorption, using a cell with a path le

Gnesinka [82]

For the absorbance of the solution in a 1.00 cm cell at 500 nm is mathematically given as

A’ = 0.16138

<h3>What is the absorbance of the solution in a 1.00 cm cell at 500 nm?</h3>

Absorbance (A) 2 – log (%T) = 2 – log (15.6) = 0.8069

Generally, the equation for the Beer’s law is mathematically given as

A = ε*c*l

0.8069 = ε*c*(5.00 )

ε*c = 0.16138 cm-1

then for when ε*c is constant

l’ = 1.00

A’ = (0.16138 cm-1)*(1.00 cm)

A’ = 0.16138

In conclusion, the absorbance of the solution in a 1.00 cm cell at 500 nm is

A’ = 0.16138