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Chemistry

1 answer:

Lynna [10]3 years ago

4 0

Answer:

Water, H2O, is a pure substance, a compound made of hydrogen and oxygen. Although water is the most abundant substance on earth, it is rarely found naturally in its pure form. Most of the time, pure water has to be created. Pure water is called distilled water or deionized water.

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Describe the three steps of solution formation. be sure to include the details regarding the dissolving of the substance

Elza [17]

The three steps involve;

Step 1: Separation/expansion of the solute particles

Step 2: Separation/expansion of the solvent particles

Step 3; Combining the solute and solvent particles

The first two steps are usually endothermic. Step 3, nonetheless, can be either exothermic or endothermic and is significant in determining whether the dissolving process will be endothermic or exothermic.

8 0

3 years ago

Read 2 more answers

What volume of 0.140 HCl is needed to neutralize 2.58 of Mg(OH)2<br> ? ...?

elena-s [515]

To make a first step you have to know the balanced form for neutralization formula: $Mg(OH)2(aq)+2HCl(aq)--\ \textgreater \ 2H2O+Mg(aq)+Cl(aq)
$
According to this, you can <span>calculate what you are being asked :</span> $0.0442molMg(OH)2(x)(2molHCl)/(1molMg(OH)2)=0.0885molHCl$
Then we have : $0.140MHCl=0.140(mol/L)HCl$
Hope everything is clear, here is the exact answer you need : $V=(0.0885molHCl)/(0.140(mol/L)HCl)=0.632LHCl
$

8 0

2 years ago

8. A sample of potassium chlorate (KCIO,) was heated in a test tube and decomposed 2KC?(s) 302 (g) + 2KCIO, (s) The oxygen was c

dangina [55]

Answer:

Partial pressure of $O_{2}$ in the gas was 733 torr and mass of $KClO_{3}$ in the sample was 2.12 g.

Explanation:

a) Total pressure of gas = (partial pressure of water vapour)+(partial pressure of $O_{2}$ )

Here partial pressure of water vapour is 21 torr and total pressure of gas is 754 torr.

So, partial pressure of $O_{2}$ = (total pressure of gas)-(partial pressure of water vapour) = (754 torr) - (21 torr) = 733 torr

b) Lets assume that $O_{2}$ behaves ideally. Hence-

PV=nRT

where P is pressure of $O_{2}$ , V is volume of $O_{2}$ , n is number of moles of $O_{2}$ , R is gas constant and T is temperature in kelvin

here P = 733 torr = $(733\times 0.001316)atm$ = 0.9646 atm

V = 0.65 L, R = 0.082 L.atm/(mol.K), T=(273+22)K = 295 K

So, $n=\frac{PV}{RT}$

= $\frac{(0.9646 atm)\times (0.65 L)}{(0.082 L.atm/(mol.K))\times (295 K)}$

= 0.0259 moles

As 3 moles of $O_{2}$ are produced from 2 moles of $KClO_{3}$ therefore 0.0259 moles of $O_{2}$ are produced from $(\frac{2\times 0.0259}{3})$ moles or 0.0173 moles of $KClO_{3}$ .