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3 years ago

TRUE OR FALSE QUESTIONS

Chemistry

2 answers:

TiliK225 [7]3 years ago

8 0

Answer:

1.T, 2.F., 3.T

Explanation:

2 is false because electrons have a negative charge neutrons have no charge

s344n2d4d5 [400]3 years ago

6 0

1: FALSE The physical properties of metals include shininess, malleability, ductility, and conductivity.

2: FALSE Neutrons are the particles in an atom that have a neutral charge. They aren't positive like protons. They aren't negative like electrons.

3: TRUE Dmitri Ivanovich Mendeleev was a Russian chemist and inventor. He is best remembered for formulating the Periodic Law and creating a farsighted version of the periodic table of elements. He is also known as the "father of the periodic table"

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Wewaii [24]

Answer: 0.0450 moles of $CaCl_2$

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

$\text{Number of moles of} CaCl_2=\frac{5.00g}{110.98g/mol}=0.0450moles$

Thus there are 0.0450 moles of $CaCl_2$

6 0

3 years ago

The question in the picture plz help and give me an explanation

zloy xaker [14]

Answer:

Explanation:

I HOPE IT HELPS :)

5 0

3 years ago

Which type of energy does alpha decay generate?(1 point)

natta225 [31]

,Answer:

kinetic energy, gamma decay, it becomes less stable by repositioning its particles

Explanation:

5 0

3 years ago

How many moles of nitrogen gas will occupy a volume of 5L at 3.85 atm and 27c?

Olegator [25]

Answer:

$n=0.78mol$

Explanation:

Hello there!

In this case, according to the given information, it possible for us to realize that this problem is solved via the ideal gas equation:

$PV=nRT$

By which we solve for n (moles) as shown below:

$n=\frac{PV}{RT}$

Then, we plug in the given pressure, volume and temperature (in K) to obtain:

$n=\frac{3.85atm*5L}{0.08206\frac{atm*L}{mol*K}*(273+27)K} \\\\n=0.78mol$

Regards!

7 0

3 years ago

The Handbook of Chemistry and Physics gives solubilities of the following compounds in grams per 100 mL water. Because these com

Elanso [62]

Answer:

(a) $Ksp=4.50x10^{-7}$

(b) $Ksp=1.55x10^{-6}$

(d) $Ksp=1.05x10^{-22}$

Explanation:

Hello,

In this case, given the solubility of each salt, we can compute their molar solubilities by using the molar masses. Afterwards, by using the mole ratio between ions, we can compute the concentration of each dissolved and therefore the solubility product:

(a) $BaSeO_4(s)\rightleftharpoons Ba^{2+}(aq)+SeO_4^{2-}(aq)$

$Molar\ solubility=\frac{0.0188g}{100mL} *\frac{1mol}{280.3g}*\frac{1000mL}{1L}=6.7x10^{-4}\frac{mol}{L}$

In such a way, as barium and selenate ions are in 1:1 molar ratio, they have the same concentration, for which the solubility product turns out:

$Ksp=[Ba^{2+}][SeO_4^{2-}]=(6.7x10^{-4}\frac{mol}{L} )^2\\\\Ksp=4.50x10^{-7}$

(B) $Ba(BrO_3)_2(s)\rightleftharpoons Ba^{2+}(aq)+2BrO_3^{-}(aq)$

$Molar\ solubility=\frac{0.30g}{100mL} *\frac{1mol}{411.15g}*\frac{1000mL}{1L}=7.30x10^{-3}\frac{mol}{L}$

In such a way, as barium and bromate ions are in 1:2 molar ratio, bromate ions have twice the concentration of barium ions, for which the solubility product turns out:

$Ksp=[Ba^{2+}][BrO_3^-]^2=(7.30x10^{-3}\frac{mol}{L})(3.65x10^{-3}\frac{mol}{L})^2\\\\Ksp=1.55x10^{-6}$

$Molar\ solubility=\frac{0.038g}{100mL} *\frac{1mol}{289.35g}*\frac{1000mL}{1L}=1.31x10^{-4}\frac{mol}{L}$

In such a way, as ammonium, magnesium and arsenate ions are in 1:1:1 molar ratio, they have the same concentrations, for which the solubility product turns out:

$Ksp=[NH_4^+][Mg^{2+}][AsO_4^{3-}]^2=(1.31x10^{-4}\frac{mol}{L})^3\\\\Ksp=2.27x10^{-12}$

(D) $La_2(MoOs)_3(s)\rightleftharpoons 2La^{3+}(aq)+3MoOs^{2-}(aq)$

$Molar\ solubility=\frac{0.00179g}{100mL} *\frac{1mol}{1136.38g}*\frac{1000mL}{1L}=1.58x10^{-5}\frac{mol}{L}$

In such a way, as the involved ions are in 2:3 molar ratio, La ion is twice the molar solubility and MoOs ion is three times it, for which the solubility product turns out:

$Ksp=[La^{3+}]^2[MoOs^{-2}]^3=(2*1.58x10^{-5}\frac{mol}{L})^2(3*1.58x10^{-5}\frac{mol}{L})^3\\\\Ksp=1.05x10^{-22}$

Best regards.

7 0

4 years ago