CHEMISTRY HIGH SCHOOL

A scientist tests a new cough medicine by giving it to a group who have colds. The scientist gives another group with colds a liquid and tells them it is cough medicine. The people in both group are women between the age of 20 and 30 who normally are in good health

Answers

Answer 1

Answer:

Here's your asnwer.

Answer 2

Answer:

Answer:

posible mente es una equivocacion porque dijo que estaban refriados y les dió una medicina para la tos

Answer : Selenium

Explanation :

The complete question is attached in the attachment.

Out of the given options, Selenium is the one which is most brittle element.

As selenium is a metalloid or a crystalline non metal which is lustrous and is ductile in nature and is highly brittle in nature.

Selenium is the most brittle out of all the other elements

A gas at 255 kilopascals and 45°C has an initial volume of 2.00L. The pressure of the gas increases to 805 kilopascals as the temperature is raised to 255°C. What will be the new volume?1.05 liters
2.28 liters
1.25 liters
0.44 liters
1.50 liters

Answers

Answer : The correct option is, (a) 1.05 liters

Solution :

Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.

The combined gas equation is,

$(P_1V_1)/(T_1)=(P_2V_2)/(T_2)$

where,

$P_1$ = initial pressure of gas = 255 kpa

$P_2$ = final pressure of gas = 805 kpa

$V_1$ = initial volume of gas = 2 L

$V_2$ = final volume of gas = ?

$T_1$ = initial temperature of gas = $45^oC=273+45=318K$

$T_2$ = final temperature of gas = $255^oC=273+255=528K$

Now put all the given values in the above equation, we get the final volume of gas.

$(255kpa* 2L)/(318K)=(805kpa* V_2)/(528K)$

$V_2=1.05L$

Therefore, the final or new volume of gas will be, 1.05 liters

Why is the total mass always conserved in a chemical reaction? Be sure that your explanation includes the discussion of atoms and bonds.

Answers

Conservation of mass means that mass can not be created and even destroyed. This hold true with energy. During a chemical reaction, atoms were never created during the process. Also, during the process they were not destroyed. Atoms just change in form, connect to a different configuration or made into smaller or larger molecules but never created or destroyed.

How many moles of C
O
2
COX
2

will be produced from
97.0
g
97.0 g97, point, 0, start text, space, g, end text of
C
3
H
8
CX
3

HX
8

, assuming
O
2
OX
2

is available in excess?

Answers

Final answer:

Given 97.0 g of propane (C3H8), about 6.6 moles of CO2 will be produced according to the balanced chemical equation for the combustion of propane.

Explanation:

The question asks how many moles of CO2 will be produced from 97.0 g of C3H8, assuming O2 is available in excess.

The balanced chemical equation for the combustion of propane (C3H8) is C3H8 + 5O2 → 3CO2 + 4H2O. This tells us that one mole of propane produces three moles of CO2.

First, we need to find the moles of propane. The molar mass of propane is approximately 44.09 g/mole. So, 97.0 g of propane corresponds to approximately 2.2 moles. Therefore, 2.2 moles of propane produce 2.2 * 3 = 6.6 moles of CO2.