All categories

3 years ago

13 This word describes the circulatory system that provides nutrients and oxygen to living cells of the body.

Chemistry

1 answer:

Nina [5.8K]3 years ago

4 0

Answer: Cardiovascular System

Explanation:

This involves your heart, blood, veins, and arteries

You might be interested in

Plz help me : Copper (I) chloride CuCl is made up of:

TEA [102]

C. Metal and Nonmetal

8 0

3 years ago

HELPPP<br> What do you think caused this land formation ?

Arturiano [62]

Answer:

Erosion/Weathering

Explanation:

Because the rock is exposed to the ocean, the constant push and pull of the water against the rock erodes the material away and moves it elsewhere. The wind likely aided in this process as well. This caused the big gap in the center of the rock.

6 0

3 years ago

Aluminum metal and manganese (IV) oxide react to produce aluminum oxide and manganese metal. What mass of manganese (IV) oxide r

gayaneshka [121]

Answer: 1.77 kg of manganese (IV) oxide reacts to produce 1.12kg of manganese metal.

Explanation:

The balanced chemical equation is:

$4Al+3MnO_2\rightarrow 2Al_2O_3+3Mn$

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

moles of manganese = $\frac{1.12\times 1000g}{55g/mol}=20.4mol$

According to stoichiometry :

3 moles of $Mn$ is produced by = 3 moles of $MnO_2$

Thus 20.4 moles of $Mn$ is produced by = $\frac{3}{3}\times 20.4=20.4moles$ of $MnO_2$

Mass of $MnO_2=moles\times {\text {Molar mass}}=20.4moles\times 86.9g/mol=1773g=1.773kg$ (1kg=1000g)

Thus 1.77 kg of manganese (IV) oxide reacts to produce 1.12kg of manganese metal.

6 0

3 years ago

A student collects 350 mL of a vapor at a temperature of 67°C. The atmospheric pressure at the time of collection is 0.900 atm.

Fed [463]

Answer:

Explanation:

This problem is very similar to the other that you put before, so, we'll use the same principle here.

The ideal gas equation: PV = nRT

Where:

P: pressure in atm

V: volume in L

T: Temperature in K.

n: moles

R: Gas constant (In this case, we'll use 0.082 L atm/K)

to get the molar mass of the gas, we need to know the moles, and with the mass, we can know the molar mass. However we can put the ideal gas expression with the molar mass in this way:

we know that n is mole so:

n = g/MM

If we put this in the idea gases expression we have:

PV = gRT/MM

Solving for MM we have:

MM = gRT/PV

Now, let's convert the temperature and volume to K and L respectively:

T = 67 + 273 = 340 K

V = 350 / 1000 = 0.35 L

Now all we have to do is put all the data into the expression:

MM = 0.79 * 0.082 * 340 / 0.9 * 0.35

MM = 22.0252 / 0.315 = 69.92 g/mol rounded 70 g/mol

Now, the closest answer of your options would be 72 g/mol. This could be easily explained because we do not use all the significant figures of all numbers, including the gas constant of R. However, all the work, calculations and procedure is correct and fine, and we only have a minimum range of 2 units.

6 0

3 years ago

How much heat is required to change temperature of 2g of water from 34°C to 68°C? (Water has a specific heat of 4.18)

statuscvo [17]

Answer: B

Explanation:

To find the amount of heat required, you would use q=mcΔT.

$q=2g(4.18J/g°C)(68-34°C)$

q=284.2 J

*Please ignore the capital A in the equation. I can't find a way to type in the degree sign into the equation without the A appearing.

4 0

3 years ago