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antiseptic1488 [7]

3 years ago

10

Use the periodic table to find the molar mass of each of the following elements. Sodium (Na): g/mol Oxygen (O): g/mol Carbon (C)

: g/mol

2 answers:

ruslelena [56]3 years ago

7 0

The Molar mass of an atom corresponds directly with its atomic mass on the periodic table.

Darya [45]3 years ago

4 0

Sodium (Na): 22.99 g/mol

Oxygen (O): 16.00 g/mol

Carbon (C): 12.01 g/mol

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Metals have high melting and boiling points and are often shiny and silvery. Which of the blocks are metals?

DanielleElmas [232]

Answer:

S and p blocks elements are considered metals while d-block elements are considered transition metals.

Explanation:

s-block consist of lithium, sodium, potassium, rubidium, cesium and francium metals.

All are these called alkali metals.

These metals have one valance electron.

These metals are soft and having low density.

They easily lose their one valance electron and form cation with +1 charge.

They have low melting points.

P- block elements includes beryllium, magnesium, calcium, strontium, barium, radium metals.

They are called alkaline earth metals.

All are these have two valance electrons.

They easily lose their valance electrons and form cation with charge of +2.

These metals are also very soft.

They form salt with halogens.

They are also very reactive metals.

8 0

3 years ago

Determine the mass of water in kg, if 4300 cal of energy is placed in water, resulting in a temperature change to 101.0 oC from

Airida [17]

Answer:

0.5059kg

Explanation:

The heat absorbed for the water is determined using the equation:7

Q = C×m×ΔT

<em>Where Q is heat absorbed (4300cal)</em>

<em>C is specific heat (1cal/g°C)</em>

<em>m is the mass in grams</em>

<em>ΔT is change in °C (101.0°C - 92.5°C = 8.5°C)</em>

<em />

Replacing:

4300cal = 1cal/g°C×m×8.5°C

505.9g = m

In kg, the mass of water is:

<h3>0.5059kg</h3>

<em />

6 0

3 years ago

Which of the following is NOT a property of an acid?

Kryger [21]

The answer here is D - bases tend to feel slippery. This is because they tend to dissolve oils on your skin, reducing the friction between your fingers or hands when you rub them together.

7 0

3 years ago

The mass of an object is 1,000 g. It has a volume of 100 mL. What is the density of the object? D= mass/volume

maxonik [38]

Answer:

10 g/ml

Explanation:

divide mass by volume means divide 1000 by 100 and your answer will be 10

4 0

3 years ago

(6) Compare a CSTR with a PFR below. a. A flow of 0.3 m3/s enters a CSTR (volume of 200 m3) with an initial concentration of spe

Dmitry [639]

Answer:

Explanation:

Given that:

The flow rate Q = 0.3 m³/s

Volume (V) = 200 m³

Initial concentration $C_o$ = 2.00 ms/l

reaction rate K = 5.09 hr⁻¹

Recall that:

$time (t) = \dfrac{V}{Q}$

$time (t) = \dfrac{200}{0.3}$

$time (t) = 666.66 \ sec$

$time (t) = \dfrac{666.66 }{3600} hrs$

$time (t) = 0.185 hrs$

$\text{Using First Order Reaction:}$

$\dfrac{dc}{dt}=kc$

where;

$t = \dfrac{1}{k} \Big( \dfrac{C_o}{C_e}-1 \Big)$

$0.185 = \dfrac{1}{5.09} \Big ( \dfrac{200}{C_e}- 1 \Big)$

$0.942 = \Big ( \dfrac{200}{C_e}- 1 \Big)$

$1+ 0.942 = \Big ( \dfrac{200}{C_e} \Big)$

$\dfrac{200}{C_e} = 1.942$

$C_e = \dfrac{200}{1.942}$

$\mathbf{C_e = 102.98 \ mg/l}$

Thus; the concentration of species in the reactant = 102.98 mg/l

b). If the plug flow reactor has the same efficiency as CSTR, Then:

$t _{PFR} = \dfrac{1}{k} \Big [ In ( \dfrac{C_o}{C_e}) \Big ]$

$\dfrac{V_{PFR}}{Q_{PFR}} = \dfrac{1}{k} \Big [ In ( \dfrac{C_o}{C_e}) \Big ]$

$\dfrac{V_{PFR}}{Q_{PFR}} = \dfrac{1}{5.09} \Big [ In ( \dfrac{200}{102.96}) \Big ]$

$\dfrac{V_{PFR}}{Q_{PFR}} =0.196 \Big [ In ( 1.942) \Big ]$

$\dfrac{V_{PFR}}{Q_{PFR}} =0.196(0.663)$

$\dfrac{V_{PFR}}{0.3 hrs} =0.196(0.663)$

$\dfrac{V_{PFR}}{0.3*3600 sec} =0.196(0.663)$

$V_{PFR} =0.196(0.663)*0.3*3600$

$V_{PFR} = 140.34 \ m^3$

The volume of the PFR is ≅ 140 m³

3 0

3 years ago