Explain an example of radiation when you feel heat without directly touching it.

Suppose that coal of density 1.5 g/cm^3 is pure carbon. (It is, in fact, much more complicated, but this is a reasonable first a

NISA [10]

Answer:

q = -6464.9 kJ

Explanation:

We are given that the heat of combustion is ∆H° = −394 kJ per mol of carbon.Therefore what we need to do is calculate how many moles of C are in the lump of coal by finding its mass since the density is given.

vol = 5.6 cm x 5.1 cm x 4.6 cm = 131.38 cm³

m = d x v = 1.5 g/cm³ x 131.38 cm³ = 197.06 g

mol C = m/MW = 197.06 g/ 12.01g/mol = 16.41 mol

q = −394 kJ /mol C x 16.41 mol C = -6464.9 kJ

7 0

3 years ago

What do Potassium and Krypton have in common and what are their differences based on their location on the periodic table?

Kamila [148]

Potassium (K) and Krypton (Kr) are in the same period, so they have the same number of electron shells. Potassium is more reactive than Krypton because it only has one valence electron.

K and Kr are both in Period 4, so they each have the n = 1, 2, 3, and 4 shells. Kr is less reactive than K because it already has a complete octet.

“Potassium (K) and Krypton (Kr) are in the same period, so they have the same number of electron shells. Krypton is more reactive than Potassium because it has a full outer shell” is incorrect because having a full outer shell means that the element is unreactive.

“Potassium (K) and Krypton (Kr) are in the same group, so they have the same number of valence electrons. They have different numbers of electron shells” is incorrect for three reasons:

1. K is in Group 1 and Kr is in Group 18.

2. K has one valence electron, and Kr has eight valence electrons.

3. They have the same number of electron shells.

“Potassium (K) and Krypton (Kr) are in the same group, so they have the same number of valence electrons. They have different numbers of electron shells” is incorrect for two reasons:

1. K and Kr have different numbers of valence electrons.

2. They have the same number of electron shells.

8 0

3 years ago

Give six examples of complex compounds.

ra1l [238]

Answer:

Examples of complex compound include potassium ferrocyanide K4[Fe(CN)6] and potassium ferricyanide K3[Fe(CN)6]. Other examples include pentaamine chloro cobalt(III) chloride [Co(NH)5Cl]Cl2 and dichlorobis platinum(IV) nitrate [Pt(en)2Cl2](NO3)2.

3 0

4 years ago

Is NaCl CH3OH LiOH or H2SO4 a bronsted acid

vesna_86 [32]

Answer:

D. H₂SO₄

Explanation:

Bronsted acids are those that donate H+ ions. In this question, H₂SO₄ is a Bronsted acid.

Note: H₂SO₄ is one of seven strong acids that you should try to memorize.

3 0

4 years ago

How do I find x mm? This is for my chemistry class.

Evgesh-ka [11]

Im guessing it might be 98.4x0.58, when you rearrange the pressure formula.

7 0

4 years ago