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3 years ago

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Which of the following are building blocks of elements A. Atoms B. Protons C. Ions 2. Atoms are made up of A. Air,water,soil B.

Protons electrons and neutrons C. Proteins electrodes and neutrons please help quick

1 answer:

Serjik [45]3 years ago

6 0

1. A - atoms

2. B - protons electrons and neutrons

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A concentrated salt solution has a mass of 5.222 g for a 5.000 mL sample.

ad-work [718]

The specific gravity or relative density of a substance is the ratio of its density to the density of a reference material. The relative density of the concentrated salt solution is 1.044.

Mathematically;

Density of the concentrated salt = mass of salt/volume of salt = 5.222 g/5.000 mL = 1.044 g/mL

In the case of specific gravity, the reference material is always water and water has a density of 1 g/mL.

Hence, specific gravity of the concentrated salt solution =

Density of concentrated salt solution/density of equal volume of water

= 1.044 g/mL/1 g/mL

= 1.044

Note that specific gravity is dimensionless.

Learn more: brainly.com/question/9638888

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2 years ago

Assertion (A): Naphthalene balls disappear with time without leaving any solid.

gogolik [260]

Explanation:

a) Both A and R are true and R is the correct

explanation of A.

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1 year ago

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6 C(s) + 3 H2(g) → 2 C6H6(l) Δ H = 49 kJ<br><br> TRUE or FALSE

VMariaS [17]

Answer:

True => ΔH°f for C₆H₆ = 49 Kj/mole

Explanation:

See Thermodynamic Properties Table in appendix of most college level general chemistry texts. The values shown are for the standard heat of formation of substances at 25°C. The Standard Heat of Formation of a substance - by definition - is the amount of heat energy gained or lost on formation of the substance from its basic elements in their standard state. C₆H₆(l) is formed from Carbon and Hydrogen in their basic standard states. All elements in their basic standard states have ΔH°f values equal to zero Kj/mole.

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3 years ago

Si se adiciona etilenglicol (compuesto no volátil) a agua destilada:

poizon [28]

Answer:

Hey hi

Explanation:

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3 years ago

Determine the theoretical yield of HCl if 60.0 g of BC13 and 37.5 g of H20 are reacted according to the following balanced react

Pie

Answer : The theoretical yield of HCl is, 56.1735 grams

Explanation : Given,

Mass of $BCl_3$ = 60 g

Mass of $H_2O$ = 37.5 g

Molar mass of $BCl_3$ = 117 g/mole

Molar mass of $H_2O$ = 18 g/mole

Molar mass of $HCl$ = 36.5 g/mole

First we have to calculate the moles of $BCl_3$ and $H_2O$ .

$\text{Moles of }BCl_3=\frac{\text{Mass of }BCl_3}{\text{Molar mass of }BCl_3}=\frac{60g}{117g/mole}=0.513moles$

$\text{Moles of }H_2O=\frac{\text{Mass of }H_2O}{\text{Molar mass of }H_2O}=\frac{37.5g}{18g/mole}=2.083moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$BCl_3(g)+3H_2O(l)\rightarrow H_3BO_3(s)+3HCl(g)$

From the balanced reaction we conclude that

As, 1 mole of $BCl_3$ react with 3 mole of $H_2O$

So, 0.513 moles of $BCl_3$ react with $3\times 0.513=1.539$ moles of $H_2O$

From this we conclude that, $H_2O$ is an excess reagent because the given moles are greater than the required moles and $BCl_3$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $HCl$ .

As, 1 mole of $BCl_3$ react to give 3 moles of $HCl$

So, 0.513 moles of $BCl_3$ react to give $3\times 0.513=1.539$ moles of $HCl$

Now we have to calculate the mass of $HCl$ .

$\text{Mass of }HCl=\text{Moles of }HCl\times \text{Molar mass of }HCl$

$\text{Mass of }HCl=(1.539mole)\times (36.5g/mole)=56.1735g$

Therefore, the theoretical yield of HCl is, 56.1735 grams

7 0

3 years ago