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3 years ago

12

Help me on these 2 science questions for brainliest pleaseeeeeee...

1 answer:

weeeeeb [17]3 years ago

6 0

Answer:

Explanation:

1:) A

Mostly just use context clues

2:) D

The climate on earth is mostly due to earth's atmosphere. So, no, the moon doesn't have similar weather

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I WILL GIVE BRAINLIEST ANSWER IN 5 MINS

snow_lady [41]

Physical Properties: Sodium bicarbonate is an odorless, white crystalline solid or fine powder. It has a slightly alkaline taste. Its density is 2.20 g mL-1 and it decomposes in temperatures above 50 ºC. The decomposition yields to sodium carbonate. It is highly soluble in water and poorly soluble in acetone and methanol. It is insoluble in ethanol.

Chemical Properties: Sodium bicarbonate is an amphoteric compounds, it means the compound has a character acids an basic at the same time. It is highly soluble in water, resulting in a slighty alkaline solution.

i hope this part helps i will continue to research on Toothpaste's properties

6 0

3 years ago

Melting can be best described as a process in which molecules

statuscvo [17]

Melting can be best described as a process in which molecules gain enough kinetic energy to be able to pass to each other.

3 0

2 years ago

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below.

UNO [17]

<u>Answer:</u> The enthalpy change of the reaction is -361.6 kJ

<u>Explanation:</u>

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

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

Moles of sodium = 0.025 moles

Molar mass of sodium = 23 g/mol

Putting values in above equation, we get:

$0.025mol=\frac{\text{Mass of sodium}}{23g/mol}\\\\\text{Mass of sodium}=(0.025mol\times 23g/mol)=0.575g$

We are given:

Mass of water = 100.00 g

Mass of sodium = 0.575 g

Mass of solution = 100.00 + 0.575 = 100.575 g

To calculate the amount of heat absorbed, we use the equation:

$q=m\times C\times \Delta T$

where,

q = amount of heat absorbed = ?

m = mass of solution = 100.575 g

C = specific heat capacity of solution = 4.18 J/g°C

$\Delta T$ = change in temperature = $(T_2-T_1)=(35.75-25.00)=10.75^oC$

Putting all the values in above equation, we get:

$q=100.575g\times 4.18J/g^oC\times 10.75^oC=4519.34J=4.52kJ$

When heat is absorbed by the solution, this means that heat is getting released by the reaction.

<u>Sign convention of heat:</u>

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

For the given chemical reaction:

$2Na(s)+2H_2O(l)\rightarrow NaOH(aq.)+H_2(g)$

When 0.025 moles of sodium is reacted, the heat released by the reaction is 4.52 kJ

So, when 2 moles of sodium will react, the heat released by the reaction will be = $\frac{4.52}{0.025}\times 2=361.6kJ$

Hence, the enthalpy change of the reaction is -361.6 kJ

6 0

3 years ago

An area in the desert where water is found is known as an.

lbvjy [14]

Answer:

Oasis

Explanation:

An area in the desert that has water in it is called an oasis.

6 0

2 years ago

What volume of the stock solution (Part A) would contain the number of moles present in the diluted solution (Part B)?

vova2212 [387]

Idk what is is i am sorry

6 0

2 years ago