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4 years ago

PLEASE ANSWER

Chemistry

2 answers:

Alchen [17]4 years ago

6 0

The answer is Q because the red it's absorbed by object Q meaning only black will show

Vinvika [58]4 years ago

4 0

Answer: C. Object Q absorbs red light, and object R reflects red light.

Explanation:

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Explain what will happen to the organisms that is affected by human activities.

Ira Lisetskai [31]

Answer:

Human activity is by far the biggest cause of habitat loss.

Humans are now responsible for causing changes in the environment that hurt animals and plant species. We take up more space on Earth for our homes and cities. We pollute habitats. ... Human activity often changes or destroys the habitats that plants and animals need to survive.

Explanation:

Human activities are the various actions for recreation, living, or necessity done by people. For instance it includes leisure, entertainment, industry, recreation, war, and exercise.

Over time, destruction of such habitats leads to reduced biodiversity, weakening the Earth's ecosystems, and ultimately posing a major threat to human life. While, significant tracts of habitat have been lost, and along with them many species of plant and animal, steps can be taken to slow and even reverse the process.

One of the most significant ways in which humans have impacted on the lives of other species is by causing climate change. Many animals, including birds and frogs, now breed much earlier in spring in Britain than they did 20 years ago. Whether or not this is having a harmful effect on them has yet to be determined.

7 0

3 years ago

Aspirin (C9H8O4) is synthesized by reacting salicylic acid (C7H6O3) with acetic anhydride (C4H6O3). The balanced equation isC7H6

prisoha [69]

Answer:

For a: The mass of acetic anhydride needed is 73.91 grams.

For b: The theoretical yield of aspirin is 130.43 grams.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For a:

Given mass of salicylic acid = $1.00\times 10^2g=100g$

Molar mass of salicylic acid = 138.121 g/mol

Putting values in equation 1, we get:

$\text{Moles of salicylic acid}=\frac{100g}{138.121g/mol}=0.724mol$

For the given chemical reaction:

$C_7H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+CH_3COOH$

By stoichiometry of the reaction:

1 mole of salicylic acid reacts with 1 mole of acetic anhydride.

So, 0.724 moles of salicylic acid will react with = $\frac{1}{1}\times 0.724=0.724mol$ of acetic anhydride.

Now, to calculate the mass of acetic anhydride, we use equation 1:

Moles of acetic anhydride = 0.724 moles

Molar mass of acetic anhydride = 102.09 g/mol

Putting values in equation 1, we get:

$0.724mol=\frac{\text{Mass of acetic anhydride}}{102.09g/mol}\\\\\text{Mass of acetic anhydride}=73.91g$

Hence, the mass of acetic anhydride needed is 73.91 grams.

For b:

By stoichiometry of the reaction:

1 mole of salicylic acid is producing 1 mole of aspirin.

So, 0.724 moles of salicylic acid will produce = $\frac{1}{1}\times 0.724=0.724mol$ of aspirin.

Now, to calculate the mass of aspirin, we use equation 1:

Moles of aspirin = 0.724 moles

Molar mass of aspirin = 180.158 g/mol

Putting values in equation 1, we get:

$0.724mol=\frac{\text{Mass of aspirin}}{180.158g/mol}\\\\\text{Mass of aspirin}=130.43g$

Hence, the theoretical yield of aspirin is 130.43 grams.

4 0

3 years ago

Two moles of propene (c3h6) gas react with nine moles of oxygen (o2) gas to produce six moles of carbon dioxide gas (co2) and si

dalvyx [7]

The stoichiometry of the reaction gives the molar ratio in which the reactants react with each other and the ratio in which products are formed.
The coefficients of the reactants in the reaction follow the stoichiometry
the balanced chemical equation for the reaction is as follows;
2C₃H₆(g) + 9O₂(g) ---> 6CO₂(g) + 6H₂O(l)

7 0

3 years ago

Read 2 more answers

A ground state hydrogen atom absorbs a photon of light having a wavelength of 92.05 nm. It then gives off a photon having a wave

vodka [1.7K]

Absorbed photon energy
Ea = hc/λ.. (Planck's equation)
Ea = hc / 92.05^-9m

Energy emitted
Ee = hc/ 1736^-9m 

Energy retained ..
∆E = Ea - Ee = hc(1/92.05^-9 - 1/1736^-9) 
∆E = (6.625^-34)(3.0^8) (1.028^7)
∆E = 2.04^-18 J 

Converting J to eV (1.60^-19 J/eV)
∆E = 2.04^-18 / 1.60^-19
∆E = 12.70 eV 

Ground state (n=1) energy for Hydrogen = - 13.60eV 

New energy state = (-13.60 + 12.70)eV = -0.85 eV 

Energy states for Hydrogen
En = - (13.60 / n²) 

n² = -13.60 / -0.85 = 16
n = 4

4 0

3 years ago

Which one is a true statement about endothermic reactions? a: More heat is given off than is put into the reaction. b :The react

Setler [38]

A because it gets hot

7 0

4 years ago