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3 years ago

The main function of the circulatory system (at least a paragraph)!

1 answer:

5 0

The circulatory system moves blood in our bodies. The blood can move oxygen and nutrients to our muscles and limbs. The heartbeat pushes the blood, and the blood cells carry glucose.

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Iodine-131 is administered orally in the form of NaI(aq) as a treatment for thyroid cancer. The half-life of iodine-131 is 8.04

evablogger [386]

Answer:

16.6 mg

Explanation:

Step 1: Calculate the rate constant (k) for Iodine-131 decay

We know the half-life is t1/2 = 8.04 day. We can calculate the rate constant using the following expression.

k = ln2 / t1/2 = ln2 / 8.04 day = 0.0862 day⁻¹

Step 2: Calculate the mass of iodine after 8.52 days

Iodine-131 decays following first-order kinetics. Given the initial mass (I₀ = 34.7 mg) and the time elapsed (t = 8.52 day), we can calculate the mass of iodine-131 using the following expression.

ln I = ln I₀ - k × t

ln I = ln 34.7 - 0.0862 day⁻¹ × 8.52 day

I = 16.6 mg

8 0

3 years ago

A sample with a molar mass of 34.00 g/mol is found to consist of 5.9783% Hydrogen and 94.0217% oxygen. Find it’s molecular formu

kozerog [31]

Answer:

The formula is H202 (hydrogen peroxide, known as hydrogen peroxide)

Explanation:

100%----34g

5, 9783%---X= (5, 9783%x 34g)/100% =2 g

1g---1 atom of H

2g----x= 2g x 1 atom of H/1g = 2 atom of H

100%----34g

94, 0217%---X= (94,0217%x 34g)/100% =32 g

16g---1 atom of 0

32g----x= 32g x 1 atom of 0/16g = 2 atom of 0

5 0

2 years ago

What is the boiling point of a solution of 76 g of water dissolved in 500 mL of acetic acid, CH3COOH?

tatuchka [14]

Answer:

127.3° C, (This is not a choice)

Explanation:

This is about the colligative property of boiling point.

ΔT = Kb . m . i

Where:

ΔT = T° boling of solution - T° boiling of pure solvent

Kb = Boiling constant

m = molal (mol/kg)

i = Van't Hoff factor (number of particles dissolved in solution)

Water is not a ionic compound, but we assume that i = 2

H₂O → H⁺ + OH⁻

T° boling of solution - 118.1°C = 0.52°C . m . 2

Mass of solvent = Solvent volume / Solvent density

Mass of solvent = 500 mL / 1.049g/mL → 476.6 g

Mol of water are mass / molar mass

76 g / 18g/m = 4.22 moles

These moles are in 476.6 g

Mol / kg = molal → 4.22 m / 0.4766 kg = 8.85 m

T° boling of solution = 0.52°C . 8.85 m . 2 + 118.1°C = 127.3°C

6 0

3 years ago

Read 2 more answers

A 6.1-kg solid sphere, made of metal whose density is 2600 kg/m3, is suspended by a cord. When the sphere is immersed in a liqui

deff fn [24]

Answer:

Density of the liquid = 1470.43 kg/m³

Explanation:

Given:

Mass of solid sphere(m) = 6.1 kg

Density of the metal = 2600 kg/m³

Thus volume of the liquid :

$Volume(V)=\frac{Mass(m)}{Density (\rho)}$

Volume of the sphere = 6.1 kg/2600 kg/m³ = 0.002346 m³

The volume of water displaced is equal to the volume of sphere (Archimedes' principle)

Volume displaced = 0.002346 m³

Buoyant force = $\rho\times gV$

Where

$\rho$ is the density of the fluid

g is the acceleration due to gravity

V is the volume displaced

The free body diagram of the sphere is shown in image.

According to image:

$mg=\rho\times gV+T$

Acceleration due to gravity = 9.81 ms⁻²

Tension force = 26 N

Applying in the equation to find the density of the liquid as:

$6.1\times 9.81=\rho\times 9.81\times 0.002346+26$

$33.841=\rho\times 9.81\times 0.002346$

$\rho=\frac{33.841}{9.81\times 0.002346}$

$\rho=1470.43 kgm^3$

<u>Thus, the density of the liquid = 1470.43 kg/m³</u>

6 0

3 years ago

A 0.02 molar solution of sodium chloride contains 0.1 mole of solute. What is the volume of the solution

Deffense [45]

Answer:

Volume of solution = 5 L

Explanation:

Given data:

Molarity of solution = 0.02 M

Moles of solute = 0.1 mol

Volume of solution = ?

Solution:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

by putting values,

0.02 M = 0.1 mol / volume of solution

Volume of solution = 0.1 mol / 0.02 M

Volume of solution = 5 L

3 0

2 years ago