Write the name for the compound whose formula is shown here Ca3(BO3) 2

How many hydrogen atoms are contained in 0.40 mL of water, given that the density of water is 1 g/ml?

Paladinen [302]

Answer:

2.676e22 atoms of Hydrogen

Explanation:

Knowing the density of water is 1g/ml, 1(g/ml)*0.4ml=0.4 grams of H2O. Knowing that there are 16 grams of H2O in 1 mole of H2O, we can set up a unit conversion of 0.4 Grams H2O * $\frac{1 mol H_2O}{18 grams H_2O}*\frac{2 mol H}{1 mol H_2O} *\frac{6.022e23 atoms of H}{1 mol H}$ =

2.676e22 atoms of Hydrogen.

3 0

3 years ago

A metal forms the fluoride MF3. Electrolysis of the molten fluoride by a current of 3.86 A for 16.2 minutes deposits 1.25 g of t

larisa86 [58]

Answer: The molar mass of the metal is 96.45 g/mol

Explanation:

The fluoride of the metal formed is $MF_3$

The oxidation half-reaction follows:

$M\rightarrow M^{3+}+3e^-$

Calculating the theoretical mass deposited by using Faraday's law, which is:

$m=\frac{M\times I\times t(s)}{n\times F}$ ......(1)

where,

m = actual mass deposited = 1.25 g

M = molar mass of metal = ?

I = average current = 3.86 A

t = time period in seconds = 16.2 min = 972 s (Conversion factor: 1 min = 60 sec)

n = number of electrons exchanged = $3mol^{-1}$

F = Faraday's constant = 96500 C

Putting values in equation 1, we get:

$1.25g=\frac{M\times 3.86A\times 972s}{3mol^{-1}\times 96500 C}\\\\M=\frac{1.25g\times 3mol^{-1}\times 96500 C}{3.86A\times 972s}\\\\M=96.45g/mol$

Hence, the molar mass of the metal is 96.45 g/mol

7 0

3 years ago

43 Which element reacts spontaneously with 1.0M HCl (aq) at room temperature?

KonstantinChe [14]

The correct answer is (4) zinc~

According to the reactivity series of metals, only zinc react with HCl (aq) at room temperature.

Hope this helps~

4 0

3 years ago

What is uranium made of? For a keynote (school)

never [62]

Pure uranium is radioactive. It will react with most nonmetallic elements to make compounds. When it comes into contact with air, a thin, black layer of uranium oxide will form on its surface. Uranium-235 is the only naturally occurring isotope that is fissile.

plz mark brainiest

7 0

3 years ago

For the reaction 2kclo3(s)→2kcl(s)+3o2(g) calculate how many grams of oxygen form when each quantity of reactant completely reac

barxatty [35]

First, we need to get the molar mass of:

KClO3 = 39.1 + 35.5 + 3*16 = 122.6 g/mol

KCl =39.1 + 35.5 = 74.6 g/mol

O2 = 16*2 = 32 g/mol

From the given equation we can see that:

every 2 moles of KClO3 gives 3 moles of O2

when mass = moles * molar mass

∴ the mass of KClO3 = (2mol of KClO3*122.6g/mol) = 245.2 g

and the mass of O2 then = 3 mol * 32g/mol = 96 g

so, 245.2 g of KClO3 gives 96 g of O2

A) 2.72 g of KClO3:

when 245.2 KClO3 gives → 96 g O2

2.72 g KClO3 gives → X

X = 2.72 g KClO3 * 96 g O2/245.2 KClO3

= 1.06 g of O2

B) 0.361 g KClO3:

when 245.2 g KClO3 gives → 96 g O2

0.361 g KClO3 gives → X

∴ X = 0.361g KClO3 * 96 g / 245.2 g

= 0.141 g of O2

C) 83.6 Kg KClO3:

when 245.2 g KClO3 gives → 96 g O2

83.6 Kg KClO3 gives → X

∴X = 83.6 Kg* 96 g O2 /245.2 g KClO3

= 32.7 Kg of O2

D) 22.4 mg of KClO3:

when 245.2 g KClO3 gives → 96 g O2

22.4 mg KClO3 gives → X

∴X = 22.4 mg * 96 g O2 / 245.2 g KClO3

= 8.8 mg of O2

7 0

3 years ago