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2 years ago

HELP WITH CHEMISTRY!!! PLeeeeeeeeeaaaaasssseee

Chemistry

2 answers:

Tcecarenko [31]2 years ago

7 0

The first question should be B as the correct answer

Bad White [126]2 years ago

3 0

The answers to your questions:

1: B.

2: True

You might be interested in

Compare and contrast: element, atom, isotope

blsea [12.9K]

Answer:

Element is made up of the atoms or isotopes. Isotopes are where only neutrons change in number, such as 3 turning to 2 or to 5. Atom is where it is not changed and it is the original, and example is instead of Carbon13 it is just Carbon. I hope this helps.

7 0

2 years ago

Read 2 more answers

What kind of thermochemical equation is represented below?

ryzh [129]

The kind of thermochemical equation represented below

that is
CaO(s) + H2O (l) = Ca(OH)2 (s) +65.2 kj

is exothermic ( answer B)
This is because its heat energy has a + sign meaning that heat is released by the reaction above.

6 0

3 years ago

A sample of He gas (3.0 L) at 5.6 atm and 25°C was combined with 4.5 L of Ne gas at 3.6 atm and 25°C at constant temperature in

In-s [12.5K]

Answer:

3.6667

Explanation:

For helium gas:

Using Boyle's law

${P_1}\times {V_1}={P_2}\times {V_2}$

Given ,

V₁ = 3.0 L

V₂ = 9.0 L

P₁ = 5.6 atm

P₂ = ?

Using above equation as:

${P_1}\times {V_1}={P_2}\times {V_2}$

${5.6}\times {3.0}={P_2}\times {9.0} atm$

${P_2}=\frac {{5.6}\times {3.0}}{9.0} atm$

${P_1}=1.8667\ atm$

The pressure exerted by the helium gas in 9.0 L flask is 1.8667 atm

For Neon gas:

Using Boyle's law

${P_1}\times {V_1}={P_2}\times {V_2}$

Given ,

V₁ = 4.5 L

V₂ = 9.0 L

P₁ = 3.6 atm

P₂ = ?

Using above equation as:

${P_1}\times {V_1}={P_2}\times {V_2}$

${3.6}\times {4.5}={P_2}\times {9.0} atm$

${P_2}=\frac {{3.6}\times {4.5}}{9.0} atm$

${P_1}=1.8\ atm$

The pressure exerted by the neon gas in 9.0 L flask is 1.8 atm

Thus total pressure = 1.8667 + 1.8 atm = 3.6667 atm.

6 0

2 years ago

g Five calcite, CaCO3 (MW 100.085 g/mol), samples of equal mass have a total mass of 12.3±0.1 g. What is the absolute uncertaint

diamong [38]

Answer:

The value is $L = 0.985 \pm 0.00801 \ g$

Explanation:

From the question we are told that

The molar mass of $CaCO_3$ is $MW = 100.085 \ g/mol$

The total mass is $m_g = 12.3 \ g$

The uncertainty of the total mass is $\Delta g = 0.1$

Generally the molar weight of calcium is $M_c = 40 g/mol$

The percentage of calcium in calcite is mathematically represented as

$C = \frac{40.07}{100.085} * 100$

$C = 40.03 \%$

Generally the mass of each sample is mathematically represented as

$m= \frac{m_g}{5}$

$m= \frac{12.3}{5}$

$m= 2.46 \ g$

Generally mass of calcium present in a single sample is mathematically represented as

$m_c = 2.46 * \frac{40.04}{100}$

$m_c = 0.985 \ g$

The uncertainty of mass of a single sample is mathematically represented as

$k = \frac{\Delta g }{5}$

$k = \frac{0.1 }{5}$

$k = 0.02\ g$

The uncertainty of mass of calcium in a single sample is mathematically represent

$G = \frac{0.02 * 40.04}{ 100}$

$G = 0.00801 \ g$

Generally the average mass of calcium in each sample is

$L = 0.985 \pm 0.00801$

6 0

2 years ago

Convert 18.9 moles to MgCl2 to formula units

Masja [62]

Answer:

18.9 moles of MgCl2 = 17.834 kg of MgCl2

Explanation:

The molecular weight of MgCl is 80.0 g/mol . So, to convert the given mole amount to grams, multiply this by this number, which is constant for all compounds with a specific composition (mass fraction).

Considering the original question was in the context of chemistry, I wanted to make it seem formal and more educational too. Hopefully that worked!

EDIT: Came up with some text around what happens inside cells that would have made it better if someone just had an issue converting units, but I doubt my answer will be accepted >.<

3 0

1 year ago