Which of the following is the method that incorporates designing sustainable living environments with agriculture?

If food burns your tongue when you eat it, it because of heat transfer by

Ganezh [65]

Confluence of conduction

3 0

3 years ago

The normal freezing point of a certain liquid

stepladder [879]

Answer : The molal freezing point depression constant of X is $4.12^oC/m$

Explanation : Given,

Mass of urea (solute) = 5.90 g

Mass of X liquid (solvent) = 450.0 g

Molar mass of urea = 60 g/mole

Formula used :

$\Delta T_f=i\times K_f\times m\\\\T^o-T_s=i\times K_f\times\frac{\text{Mass of urea}\times 1000}{\text{Molar mass of urea}\times \text{Mass of X liquid}}$

where,

$\Delta T_f$ = change in freezing point

$\Delta T_s$ = freezing point of solution = $-0.5^oC$

$\Delta T^o$ = freezing point of liquid X= $0.4^oC$

i = Van't Hoff factor = 1 (for non-electrolyte)

$K_f$ = molal freezing point depression constant of X = ?

m = molality

Now put all the given values in this formula, we get

$[0.4-(-0.5)]^oC=1\times k_f\times \frac{5.90g\times 1000}{60g/mol\times 450.0g}$

$k_f=4.12^oC/m$

Therefore, the molal freezing point depression constant of X is $4.12^oC/m$

4 0

4 years ago

HELP

Vesnalui [34]

Answer:

145.8g

Explanation:

Given parameters:

Number of moles of magnesium hydroxide = 2.5mol

Unknown:

Mass of Mg(OH)₂ = ?

Solution:

To solve this problem we use the expression below;

Mass of Mg(OH)₂ = number of moles x molar mass

Molar mass of Mg(OH)₂ = 24.3 + 2(16 + 1) = 58.3g/mol

Mass of Mg(OH)₂ = 2.5 x 58.3 = 145.8g

3 0

3 years ago

A 5.00-mL sample of blood was treated with trichloroacetic acid to precipitate proteins. After centrifugation, the resulting sol

Anarel [89]

Explanation:

According to the Beer-lambert' s law,

Absrobance = absrobptitvity × lenght × concentration

So, if we will plot a graph between absrobance and concentration then we will obtain a straight line

Hence, formula to calculate slope of the graph is as follows.

The slope of graph = $\frac{\text{difference in absrobance at two points}}{\text{difference in concentrations at those points}}$

The given data is as follows.

$A_{1}$ = 0.412 (first point)

$A_{2}$ = 0.642 (second point)

$C_{1}$ = 0.240 ppm (first point)

$C_{2}$ = 0.475 ppm (second point)

Hence, putting these values into the above formula we will calculate the value of slope as follows.

Slope = $\frac{\text{difference in absrobance at two points}}{\text{difference in concentrations at those points}}$

= $\frac{0.642 - 0.412}{0.475 - 0.240}$

= $\frac{0.23}{0.235}$

= 0.978

It is known that for the graph, line equation can be written as follows.

y = mx + c ........... (1)

where, C = intercept

m = slope

Hence, calculate the value of intercept as follows.

0.412 = $0.24 \times 0.978$ + c

c = 0.178

As it is given that the absorbance values 0.454 (the y-axis value). Therefore, putting this value into equation (1) we get the following.

y = mx + c

0.454 = $x \times 0.978$ + 0.178

0.276 = 0.978x

x = 0.282 ppm

Thus, we can conclude that the concentration of Pb in the given sample is 0.282 ppm.

3 0

4 years ago

What is the frequency of the sinusoidal graph?

Arisa [49]

Answer:

For finding frequency, we need to first find the period of the graph.

The period of a sinusoidal graph is the time interval in which it repeats its pattern.

In the graph, we can see, after $1/period$ time, it repeats its pattern.

Hence the period of the graph is $\pi /2$ .

Now we need to find its frequency $1/\pi /2$

The formula for frequency is $2/\pi$

This is the answer

i hope you pass the assignment

try your best!

8 0

3 years ago