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3 years ago

I need help. Please help me on the question

Chemistry

1 answer:

horsena [70]3 years ago

5 0

Th answer is A. Hormones are chemical receptors and the x structure is taking it to the nucleus

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consider the reaction between calcium oxide and carbon dioxide: cao ( s ) + co 2 ( g ) → caco 3 ( s ) a chemist allows 14.4 g of

MakcuM [25]

Answer:

CaO is the limiting reagent

Theoritical yield = 25.71 g

% Yield = 75.44%

Explanation:

1 mole = Molar mass of the substance

Molar Mass of CaO = 56 g/mol

Molar Mass of CaCO3 = 100 g/mol

Molar mass of CO2 = 44 g/mol

The balanced Equation is :

$CaO + CO_{2}\rightarrow CaCO_{3}$

1 mole of CaO reacts with = 1 mole of CO2

56 g of CaO reacts with = 44 g of CO2

1 g of CaO reacts with =

$\frac{44}{56}$

= 0.785 g of CO2

So,

14.4 g of CaO must react with = (14.4 x 0.785) g of CO2

= 11.31 g of CO2

Needed = 11.31 g

Available CO2 = 13.8 g (given)

So CO2 is in excess , hence CaO is the limiting reagent and product will produce from 14.4 g of CaO

$CaO + CO_{2}\rightarrow CaCO_{3}$

1 mole of CaO will produce 1 mole pf CaCO3

56 g of CaO produce = 100 g of CaCO3

1 g of CaO produce =

$\frac{100}{56}$

= 1.785 g of CaCO3

14.4 g of CaO will produce = (1.785 x 14.4) g of CaCO3

= 25.71 g of CaCO3

Theoritical Yield of CaCO3 = 25.71 g

Actual yield = 19.4 g

Percent Yield =

$\frac{Actual\ yield}{Theoritical\ yield}\times 100$

$\frac{19.4}{25.71}\times 100$

= 75.44 %

6 0

3 years ago

What is mass? How is the mass of an object determined?

mina [271]

Mass is the inside of an obeject such as what it’s made up of

8 0

4 years ago

Explain about a method in which a scientist could use fossils to determine the age of the soil in which the fossils were found

Neko [114]

The method scientists could use is radiocarbon dating. This method involves the analysis of a specific type of carbon atom in fossils. Carbon 14 is radioactive and has a half-life of approximately 5730 years. By measuring the amount of carbon 14 left in a sample scientist should be able to determine the approximate time when the soil was laid down.

3 0

3 years ago

ead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0012 %Pb by mass. How mu

Flura [38]

Answer:

1.3 × 10⁴ mL

Explanation:

A Pb-contaminated water sample contains 0.0012 %Pb by mass, that is, there are 0.0012 g of Pb in 100 g of solution. The mass of the sample that contains 150 mg (0.150 g) of Pb is:

0.150 g Pb × (100 g sample/0.0012 g Pb) = 1.25 × 10⁴ g sample

The density of the sample is 1.0 g/mL. The volume of the sample is:

1.25 × 10⁴ g × (1 mL/1.0 g) = 1.3 × 10⁴ mL

7 0

3 years ago

Consider a homogeneous mixture, such as a

gogolik [260]

Answer: yes

Explanation:

6 0

3 years ago