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3 years ago

How do scientists distinguish between an element and a compound? List two elements and two compounds.

1 answer:

7 0

The difference between an element and a compound is that an element is composed of only one kind of atom while a compound is composed of at least 2 kinds of atoms. The properties of an element and the compound the atoms has to form are different physically and chemically.Example of element are O and H, while compound examples are H2O and H2O2.

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Question 15 need this answered asap (chemistry)

Tcecarenko [31]

Answer:

80.7 L

Explanation:

PV = nRT

P = 1520 mmHg = 2 atm

n = 5 mol

R = 0.08206 (L * atm)/(mol * K)

T = 393.15 K

2 (V) = 5 (0.08206) (393.15)

V ≈ 80.7 L

8 0

2 years ago

If you mix 50mL of 0.1 M TRIS acid with 60 mL of0.2 M TRIS base, what will be the resulting pH?

Katyanochek1 [597]

Answer: The pH of resulting solution is 8.7

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$

For TRIS acid:

Molarity of TRIS acid solution = 0.1 M

Volume of solution = 50 mL

Putting values in above equation, we get:

$0.1M=\frac{\text{Moles of TRIS acid}\times 1000}{50mL}\\\\\text{Moles of TRIS acid}=0.005mol$

For TRIS base:

Molarity of TRIS base solution = 0.2 M

Volume of solution = 60 mL

Putting values in above equation, we get:

$0.2M=\frac{\text{Moles of TRIS base}\times 1000}{60mL}\\\\\text{Moles of TRIS base}=0.012mol$

Volume of solution = 50 + 60 = 110 mL = 0.11 L (Conversion factor: 1 L = 1000 mL)

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[salt]}{[acid]})$

$pH=pK_a+\log(\frac{[\text{TRIS base}]}{[\text{TRIS acid}]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of TRIS acid = 8.3

$[\text{TRIS acid}]=\frac{0.005}{0.11}$

$[\text{TRIS base}]=\frac{0.012}{0.11}$

pH = ?

Putting values in above equation, we get:

$pH=8.3+\log(\frac{0.012/0.11}{0.005/0.11})\\\\pH=8.7$

Hence, the pH of resulting solution is 8.7

6 0

3 years ago

The atomic mass is equal to what?

dsp73

Answer:

The mass number

Explanation:

I hope this helps.

4 0

2 years ago

Read 2 more answers

A chemist takes 50-gram sample of sulfur powder that has a melting point of 115.2 °C. What is the melting point of a 100-gram sa

Viktor [21]

Answer:

115.2 °C since melting point is an intensive property

Step-by-step explanation:

The melting point of a substance does not depend on how much you have.

For example, the melting point of water is 0 °C, whether it is an ice cube from the refrigerator or in the frozen pond outside.

The freezing point of a substance is an intensive property.

Thus, the melting point of 100 g of sulfur is 115.2 °C because melting point in an intensive property.

7 0

2 years ago

Electron transfer is the term for this process. The resulting anion and cation are attracted by Coulombic forces and an ionic co

Nitella [24]

<h2>The compound formed is NaCl and $CaCl_{2}$ </h2>

Explanation:

PART 1:

Atomic number of sodium is 11.
Sodium(Na, Z = 11, Group 1A) will lose 1 electron to become $Na^{1+}$ which is isoelectronic to Neon (Ne ,Z = 10).
The symbol for the sodium ion is $Na^{+}$ .
Chlorine atom ( $Cl$ , Z = 17, Group 7A or 17) gains 1 elecron to be isoelectronic to neon.
The symbol for the compound formed is NaCl.
PART 2:
Atomic number of calcium is 20
Calcium(Ca, Z = 20 ,Group 2A) will lose two electrons to become $Ca^{2+}$ which is isoelectronic to argon.
The symbol for the ion is $Ca^{2+}.$
Two chlorine atoms (Cl, Z = 17, Group 7A or 17) each gains one electron to be isoelectronic to argon(Z = 18)
The symbol for the compound formed is $CaCl_{2}$ .

8 0

3 years ago