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3 years ago

What is the current temperature to the nearest degree for the thermometer shown below?

Chemistry

2 answers:

kicyunya [14]3 years ago

6 0

Answer: -2

Explanation:

For the lad on edg

padilas [110]3 years ago

3 0

There is no temperature at all shown below. Is that the same as Absolute Zero ?

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If the atomic mass is 14 and the atomic number is 7,how many neutrons do you have?

Nitella [24]

Answer: 7 neutrons

Explanation: Atomic number refers to the number of protons in the nucleus of the atom. Also you can treat atomic mass as how many particles (protons and neutrons) are in the nucleus of the atom. So for this problem:

14 particles - 7 protons = 7 neutrons (and we know all that's left over is neutrons because we subtracted all the protons)

8 0

3 years ago

Before it was launched, a helium-filled balloon had a pressure of 101 kPa at a temperature of 20°C. At an altitude of 15 000 m,

bogdanovich [222]

Answer:

5.54 m³.

Explanation:

We should use the ideal gas law: PV = nRT,

where, P is the pressure of the gas in atm,

V is the volume of the gas in L,

n is the number of moles in mole,

R is the general gas constant (R = 0.082 L.atm/mol),

T is the temperature of the gas in K.

We have two different cases at different (P, V and T) while the number of moles of He and R is constants.

∴ (P₁V₁) / (T₁) = (P₂V₂) / (T₂).

We can use P in KPa and V in m³ that the conversion factor can be canceled by division, but we should use T in K because its conversion factor is additive value.

P₁ = 101.0 kPa, V₁ = ??? m³, and T₁ = (20 °C + 273) = 293.0 K.

P₂ = 11.7 kPa, V₂ = 35.4 m³, and T₂ = (-56 °C + 273) = 217 K.

∴ The initial volume (V₁) = (P₂V₂T₁) / (P₁T₂) = (11.7 kPa)(35.4 m³)(293.0 K) / (101.0 kPa)(217.0 K) = (121354.74) / (21917) = 5.537 m³ ≅ 5.54 m³.

7 0

3 years ago

The ionic naming rules

natulia [17]

Identify and name the cation; this is a metal element or polyatomic cation.

Identify and name the anion; this is a nonmetal element. Change the suffix to '-ide,' or use the polyatomic anion name.

7 0

3 years ago

Two chemicals A and B are combined to form a chemical C. The rate, or velocity, of the reaction is proportional to the product o

stiv31 [10]

Answer:

Follows are the solution:

Explanation:

A + B = C

Its response decreases over time as well as consumption of a reactants.

r = -kAB

during response A convert into 2x while B convert into x to form 3x of C

let's y = C

y = 3x

Still not converted sum of reaction

for A: 100 - 2x

for B: 50 - x

Shift of x over time

$\frac{dx}{dt} = \frac{-k(100 - 2x)}{(50 - x)}$

Integration of x as regards t

$\frac{1}{[(100 - 2x)(50 - x)]} dx = -k dt\\\\\frac{1}{2[(50 - x)(50 - x)]} dx = -k dt\\\\\ integral\ \frac{1}{2[(50 - x)^2]} dx =\ integral [-k ] \ dt\\\\\frac{-1}{[100-2x]} = -kt + D \\\\$

D is the constant of integration

initial conditions: t = 0, x = 0

$\frac{-1}{[100-2x]} = -kt + D \\\\\frac{ -1}{[100]} = 0 + D\\\\D= \frac{-1}{100}\\\\$

hence we get:

$\frac{-1}{[100-2x]}= -kt -\frac{1}{100}\\\\or \\\\ \frac{1}{(100-2x)} = kt + \frac{1}{100}$

after t = 7 minutes , $C = 10 \ g = 3x$

$3x = 10\\\\x = \frac{10}{3}$

Insert the above value x into $\frac{1}{(100-2x)}$ equation $= kt + \frac{1}{100}$ to get k.

$\to \frac{1}{(100-2\times \frac{10}{3})} = k \times (7) + \frac{1}{100} \\\\ \to \frac{1}{(100- 2 \times 3.33)} = \frac{700k + 1}{100} \\\\ \to \frac{1}{(100-6.66)} = \frac{700k + 1}{100}\\\\ \to \frac{1}{93.34} = \frac{700k + 1}{100} \\\\$

$\to 100 = 93.34(700k + 1) \\\\ \to 100 = 65,338k + 700 \\\\ \to 65,338k = -600 \\\\ \to k = \frac{-600}{ 65,338} \\\\ \to k= - 0.0091$

therefore plugging in the equation the above value of k

$\to \frac{1}{(100-2x)} = kt +\frac{1}{100} \\\\\to \frac{1}{(100-2x)} = -0.0091t + \frac{1}{100}\\\\\to \frac{1}{(100-2x)} = \frac{1 -0.91t}{100}\\\\\to \frac{1}{2(50-x)} = \frac{1 -0.91t}{100}\\\\\to \frac{1}{(50-x)} = \frac{1 -0.91t}{50}\\\\\to 50= (1-0.91t)(50-x)\\\\\to 50 = 50-45.5t-x-0.91tx\\\\\to x+0.91xt= -45.5t\\\\\to x(1+0.91t)= -45.5t\\\\\to x=\frac{-45.5t}{1+0.91t}$

Let y = C

, calculate C:

y = 3x

$y =3 \times \frac{-45.5t}{1+0.91t}$

amount of C formed in 28 mins

$x = \frac{-45.5t}{1+0.91t} ,$ plug t = 28

$\to x = \frac{-1274}{1+25.48} \\\\\to x = \frac{-1274}{26.48} \\\\\to x= -48.26$

therefore amount of C formed in 28 minutes is = 3x = 144.78 grams

C: $y =3 \times \frac{-45.5t}{1+0.91t}$

y= 136.5 =137

7 0

3 years ago

How many molecules are in 20.2 moles of CO₂?

mrs_skeptik [129]

Answer:

1.22 x 10²⁵ molecules CO₂

Explanation:

To find the amount of molecules, you need to multiply the number of moles by Avogadro's Number. Avogadro's Number is a ratio which represents the amount of molecules per every 1 mole. It is important to arrange this ratio in a way that allows for the cancellation of units (since you are going from moles to molecules, moles should be in the denominator). The final answer should have 3 sig figs like the given value.

Avogadro's Number:

6.022 x 10²³ molecules = 1 mole

20.2 moles CO₂ 6.022 x 10²³ molecules
--------------------------- x -------------------------------------- = 1.22 x 10²⁵ molecules
1 mole

8 0

1 year ago