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2 years ago

Hich of the following best describes a person doing science?

Chemistry

2 answers:

12345 [234]2 years ago

7 0

Answer:

i think its B

Explanation:

miss Akunina [59]2 years ago

4 0

Answer:

I think it is answer B. what grade are you in? im in 7th.

Explanation:

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The mass of the sun<br> what is the mass of the sun

Blizzard [7]

Answer:

1.989 × 10^30 kg

Explanation:

Hope this helps! :3

8 0

3 years ago

Read 2 more answers

5 grams of NaHCO3 was added to 50 cm3 of 1.5 mol dm-3 hydrochloric acid, causing the temperature to decrease by 6.8 K. What is t

Gelneren [198K]

The chemical equation representing the neutralization reaction between HCl and $NaHCO_{3}$ is,

$HCl (aq) + NaHCO_{3}(aq)--> NaCl (aq) + H_{2}O(l)+CO_{2} (g)$

Given mass of $NaHCO_{3}$ = 5g

Moles of $NaHCO_{3}$ = $5 g *\frac{1 mol}{84 g} = 0.05952 mol NaHCO_{3}$

Volume of HCl solution = $50 cm^{3} * \frac{1 mL}{1cm^{3}} = 50 mL$

Assuming the density of solution to be 1.0 g/mL

Mass of HCl solution = 50 g

Total mass of solution = 50 g+ 5 g = 55 g

Calculating the heat of neutralization:

Q = m C ΔT

m is mass of solution = 55 g

C is the specific heat capacity of the solution = 4.184 $\frac{J}{g. ^{0}C}$

ΔT = Temperature difference = 6.8 K = (6.8 -273 ) C = -266.2 $^{0}C$

$Q = 55 g * 4.184 \frac{J}{g. K}(6.8K) = 1565 J$

Enthalpy of neutralization per mole of $NaHCO_{3}$

= $\frac{1565J}{0.05952 mol} = 26294 \frac{J}{mol}*\frac{1 kJ}{1000J} =26.294kJ/mol$

3 0

3 years ago

Read 2 more answers

Imagine that you could dive deep into the Atlantic Ocean where the South American plate and African plate meet at a plate bounda

Alex787 [66]

Answer:

At the plate boundary, there would be a divergent boundary where we can see a mid ocean ridge and a gap. We would be able to see the mantle because there would be a fissure from where magma will rise and solidify.

Explanation:

Under the South American plate and African plate, there are currents that cause a divergent boundary. They create this boundary since they pull the tectonic plates apart, causing a mid-ocean ridge with an opening that allows the rising of the magma that was underneath. Once that the magma is out, it solidifies, and the currents will try to create another ridge to repeat the process.

When the plates are apart, the mantle that is beneath is exposed, and we can see the magma.

4 0

2 years ago

Are bath bombs covalent or ionic bonds?

lubasha [3.4K]

Bath Bombs are colvalent bonds because they have both metals and non-metals before and after it makes contact with water.

4 0

2 years ago

When 1 mole of H2(g) reacts with F2(g) to form HF(g) according to the following equation, 542 kJ of energy are evolved H2(g) + F

topjm [15]

Answer: The reaction is exothermic. The value of q is -542 kJ.

Explanation:

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and for the reaction comes out to be negative.

Thus $H_2(g)+F_2(g)\rightarrow 2HF(g)$ evolves heat , it is exothermic in nature. The value of q is -542kJ.

7 0

2 years ago