Sign convention of work and heat

How many sig figs are in 0.0003422

Ivenika [448]

Answer:

4

Explanation:

The zeros before a non zero digit do not count as significant figures so there are 4 sig figs in the number

5 0

3 years ago

Write the balanced chemical equation for the following reaction. Phases are optional. Solid calcium chlorate decomposes to form

Tanya [424]

Answer:

Ca(ClO₃)₂ (s) → CaCl₂ (s) + 3O₂ (g)

Explanation:

1) Word equation (given)

calcium chlorate (solid) → solid calcium chloride (solid) + oxygen (gas)

2) Chemical formulae of the reactant and products:

Calcium chlorate:

The most common oxidation states of chlorine are -1, +1, +3, +5, +7.

The suffix ate in chlorate means that chlorine atom is with the third lowest oxidation state (counting only the positive states). So, this is +5.

The oxidation state of calcium is +2.

Hence, the chemical formula of calcium chlorate is Ca(ClO₃)₂

Calcium chloride

The suffix ide in chloride means that chlorine is with oxidation state -1. Again the oxidation state of calcium is +2.

Hence, the chemical formula of calcium chloride is CaCl₂

Oxygen

Oxygen gas is a diatomic molecule, so its chemical formula is O₂.

Phases

The symbols s and g (in parenthesis) indicate the solid and gas phases respectively.

3) Chemical equation:

Ca(ClO₃)₂ (s) → CaCl₂ (s) + O₂ (g)

That equation is not balanced becasue the number of O atoms in the reactant side and in the product side are different.

4) Balanced chemical equation:

Add a 3 as coefficient in front of O₂(g), in the product side to balance:

Ca(ClO₃)₂ (s) → CaCl₂ (s) + 3O₂ (g)

Verify that all the atoms are balanced:

Atom Reactant side Product side

Ca 1 1

Cl 2 2

O 3×2 = 6 2×3 = 6

Conclusion: the equation is balanced and the final answer is:

Ca(ClO₃)₂ (s) → CaCl₂ (s) + 3O₂ (g)

5 0

3 years ago

Complete the hybridization and bonding scheme for xef4.

Vikentia [17]

Xe = VIII = 8 valence electrons
F = VII = 4 (7 ve) = 28 valence electrons

total ve = 8 + 28 = 36 ve

36 - 4(2) = 28 ve
(there are 2 electrons in each bond x 4 bonds)

28 - 4(6) = 4
(We assign the remaining electrons to F atoms)

4 - 2(2) = 0
(Therefore 4 electrons left => we have 2 lone pairs)

The steric number = No. of σ bonds + #lone pairs

= 4 σ bonds + 2 lone pairs = 6 => d²sp³ (6 hybrid orbitals)

4 bonds + 2 lone pairs => square planar

6 0

3 years ago

Use the data given below to construct a Born-Haber cycle to determine the heat of formation of KCl. Δ H°(kJ) K(s) → K(g) 89 K(g)

AURORKA [14]

Explanation:

The net equation will be as follows.

$K(s) + Cl_{2}(g) \rightarrow KCl(s)$

So, we are required to find $\Delta H_{formation}$ for this reaction.

Therefore, steps involved for the above process are as follows.

Step 1: Convert K from solid state to gaseous state

$K(s) \rightarrow K(g)$ , $\Delta H_{1}$ = 89 kJ

Step 2: Ionization of gaseous K

$K(g) \rightarrow K^{+}(g) + e^{-}$ , $H_{2}$ = 418 KJ

Step 3: Dissociation of $Cl_{2}$ gas into chlorine atom .

$\frac{1}{2} Cl_{2}(g) \rightarrow Cl(g)$ , $\Delta H_{3} = \frac{244}{2}$ = 122 KJ

Step 4: Iozination of chlorine atom.

$Cl(g) + e^{-} \rightarro Cl^{-}(g)$ , $H_{4}$ = -349 KJ

Step 5: Add $K^{+}$ ion and $Cl^{-}$ ion formed above to get KCl .

$K^{+}(g) + Cl^{-}(g) \rightarrow KCl(s)$ , $H_{5}$ = -717 KJ

Now, using Born-Haber cycle, value of enthalpy of the formation is calculated as follows.

$\Delta H_{f} = \DeltaH_{1} + \Delta H_{2} + \Delta H_{3} + \Delta H_{4} + \Delta H_{5}$

= 89 + 418 + 122 - 349 - 717

= - 437 KJ/mol

Thus, we can conclude that the heat of formation of KCl is - 437 KJ/mol.

5 0

3 years ago

Commercial utilization of microbial products has become increasingly popular due to their environmentally friendly nature. Produ

Stells [14]

Answer: enzymes.

Explanation:

Microbial products are products derived from microorganisms. They may be primary or secondary metabolites. They are known to be environment friendly since they have biological origin. They are often degraded by enzymes which are also biological molecules. Degradation of materials using enzymes typically generates nontoxic products.

4 0

3 years ago

Sign convention of work and heat​

Sign convention of work and heat