When was this device used to kill criminals/traitors?

Answer:

0.010 $.

Explanation:

Hello!

In this case, since 1 troy ounce equals 31.1 grams, we can compute the price of gold per gram first:

[tex]1,838.80\frac{\$}{try\ ounce} * \frac{1try\ ounce}{31.1g} = 59.1\frac{\$}{g}[/tex]

Now, we need to compute the grams of copper in 5.17 x10¹⁷ atoms via the Avogadro's number:

[tex]m=5.17x10^{17}atomsAu*\frac{197.0gAu}{6.022x10^{23}atomsAu} \\\\m=1.69x10^{-4}g[/tex]

Thus, the price is:

[tex]\$ = 59.1\frac{\$}{g}*1.69x10^{-4}g \\\\\$ =0.010\$[/tex]

Best regards!

Answer: 2 H2 + O2 → 2 H2O, you get the same number of moles of water as H2, as long as you have 1 mole of O2. So, with 3 moles of H2, as long as you have 1.5 moles of O2, you will get 3 moles of H2O. In my opinion.

Answer:

Again, nitrogen dioxide does not follow the octet rule for one of its atoms, namely nitrogen. The total number of valence electrons is 5+2(6)=17. There is persistent radical character on nitrogen because it has an unpaired electron. The two oxygen atoms in this molecule follow the octet rule.

C

Sana makatulong answer ko

Answer:

electron and ignore this woejdnks

Answer:

2.2moles

Explanation:

Given parameters:

Atomic mass of Radium = 226

Mass of Radium  = 497.2g

Unknown:

Number of moles  = ?

Solution:

To solve this problem, we use the expression below:

    Number of moles  = [tex]\frac{mass}{molar mass}[/tex]

The molar mass of the radium   = 226g/mol

So;

       Number of moles  = [tex]\frac{497.2}{226}[/tex]   = 2.2moles

Answer:

dunno

Explanation:

sorry

Answer:

32.76mole of P

Explanation:

The reaction expression is given as;

          P₄O₁₀  →    4P  +  5O₂

Given parameters:

Number of moles of   P₄O₁₀  = 8.19mol

Unknown:

Number of moles of P produced = ?

Solution:

From the balanced reaction expression;

             1 mole of P₄O₁₀  will produce 4 mole of P

         8.19mole of P₄O₁₀  will therefore produce 4 x 8.19  = 32.76mole of P

Answer:

1.93391595 grams I hope this helps

Explanation:

Answer:

0.85 mL

Explanation:

Step 1: Given data

Step 2: Calculate the volume of the aluminum block

Density is an instrisic property. It is equal to the mass of the block divided by its volume.

ρ = m/V

V = m/ρ

V = 2.3 g/(2.7 g/mL)

V = 0.85 mL

Answer:

cointreau, tequila,lime juice

Answer:See explanation

Explanation:

MOLECULAR REACTION EQUATION;

Al(NO3)3(aq) + 3NaOH(aq) --->Al(OH)3(s) +3NaNO3(aq)

complete ionic equation:

Al^3+(aq) + 3NO3^-(aq)  + 3Na^+(aq) + 3OH^-(aq) ---->Al(OH)3(s) + 3Na^+(aq) + 3NO3^-(aq)

Net ionic reaction equation;

Al^3+(aq) + 3OH^-(aq) ------> Al(OH)3(s)

Answer:

True

Explanation:

When ice is heated, the ice gains heat.

This heat gained by the ice is both used to break the intermolecular forces in ice to form water, as well as to raise the temperature of the water to it's final temperature.

Answer:

1. decreases

2. Transverse

3. Vibrations

Answer:

[tex]m_{H_2O_2}=0.317gH_2O_2[/tex]

Explanation:

Hello!

In this case, for the chemical reaction between hydrochloric acid and barium peroxide is:

[tex]BaO_2(s)+2HCl(aq)\rightarrow H_2O_2(aq)+BaCl_2(aq)[/tex]

Thus, since the barium peroxide (169.33 g/mol) and hydrochloric acid (36.45 g/mol) are reacting in a 1:2 mole ratio, we need to identify the limiting reactant first by computing the yielded moles of hydrogen peroxide by each reactant:

[tex]n_{H_2O_2}^{by\ BaO_2}=1.50gBaO_2*\frac{1molBaO_2}{169.33gBaO_2}*\frac{1molH_2O_2}{1molBaO_2}=0.00886molH_2O_2\\\\ n_{H_2O_2}^{by\ HCl}=0.0272\frac{gHCl}{mL}*25.0mL *\frac{1molHCl}{36.46gHCl}*\frac{1molH_2O_2}{2molHCl}=0.00933molH_2O_2[/tex]

That's why the HCl is the limiting reactant, so the resulting mass of hydrogen peroxide, theoretical yield, is:

[tex]m_{H_2O_2}=0.00933molH_2O_2*\frac{34.02gH_2O_2}{1molH_2O_2}\\\\m_{H_2O_2}=0.317gH_2O_2[/tex]

Best regards!

Answer:it has one proton,

and one electron

Explanation:

It has one neutron and It has one nucleon

Answer:

Answer:

A. 16.0 grams

B. 3.1 mol of oxygen

Explanation:

A.

The oxygen atom has mass = 2.66x10^-23g

A mole of oxygen atoms can be calculated as:

[2.66x10^-23/1 oxygen atom] x [6.023x10²³ oxygen atoms/1 mol]

= 16.0 grams of oxygen

So a mole of oxygen has 16.0 grams of O2

B.

For 0.050 kg of water, we have 16.0 grams

(0.050x10³g/kg )x (1mol/16)

= 3.1 mol of oxygen

So 3.1 mol of oxygen has mass which is equal to the mass of water.

The [OH-] of NaF solution : 1.7 x 10⁻⁶

Given

0.2 M NaF

Ka of HF is 7.1 x 10⁻⁴

Required

[OH⁻]

Solution

Hydrolysis of NaF salt which is formed from weak acid HF and strong base NaOH

F⁻(aq) + H₂O(l) ⇄ HF(aq) + OH⁻(aq)

General formula :

[tex]\tt [OH^-]=\sqrt{\dfrac{Kw}{Ka}\times M }[/tex]

Input the value :

[OH⁻]=√(10⁻¹⁴/7.1 x 10⁻⁴) x 0.2

[OH⁻]= 1.678 x 10⁻⁶ ≈ 1.7 x 10⁻⁶

Answer:Moles of Mg, Cl,  0 =  5.40, 10.80, 43.2

Explanation:

1  mole of Mg(ClO4)2  contains  1 mole of Magnesium, Mg atoms

                                                    2 Moles of Chlorine, Cl atoms

                                                    8 Molresof Oxygen atoms

Such that to find the number of moles of each element, We have that

------1 mole Magnesum  atoms/ 1 mol of  Mg(ClO4)2   x 5.40 moles  of magnesium perchlorate, Mg(ClO4)2 = 1 x 5.40 =5.40 moles

------2 moles ofChlorine atoms/ 1 mol of Mg(ClO4)2   x 5.40 moles of magnesium perchlorate, Mg(ClO4)2 = 2 x 5.40 = 10.80 moles

------8 moles Oxygen atoms/ 1 mol of  Mg(ClO4)2   x 5.40 moles  of magnesium perchlorate, Mg(ClO4)2 = 8 x 5.40 = 43.2 moles

Answer:

Mole fraction for benzene is 0.683

Explanation:

We need to determine the colligative property about vapour pressure which formula is:

ΔP = P° . Xm

where P° is vapour pressure of pure solvent.

ΔP = Vapor pressure of pure solvent - Vapor pressure of solution

In this case, our solvent is benzene and the solute is toluene. For this colligative property vapour pressure of solution is lower than pure solvent.

P° of benzene at 20°C is 74.7 Torr

Xm is the value for the mole fraction of solute.

Let's replace data: 74.7 Torr - 51 Torr = 74.7 Torr . Xm

Xm = 0.317 → That's the mole fraction for toluene.

Then, mole fraction for benzene will be: 1 - 0.317 → 0.683

Answer:

168.56

Explanation:

Answer:

48 grams

Explanation:

If p and V are already given, calculate m by multiplying those two values.

m = pV

m = 4/5 * 60/1

m = 240/5

m = 48 grams

The mass of that substance is 48 grams.

Answer:

12.1% C, 16.1% O, 71.8% Cl

Explanation:

i hope this is correct

Answer:

1. the group number of sodium is 1 and it is a metal

2. the group number of helium is 18 and it is a nonmetal

3. the group number of iodine is 17 and it is a nonmetal

4.the group number of calcium is 2 and it is a metal

5. lithium has similar properties to potassium

6. calcium has similar properties to magnesium

7. neon has similar properties to xenon

8. Iodine has similar properties to chlorine

Answer:

The electron pair geometry is Trigonal planar

Molecular geometry - Bent

Approximate bond angle - <120°

Explanation:

The valence shell electron pair repulsion theory enables us to predict the shapes of molecules based on the number of electron pairs present on the valence shell of the central atom and based on the hybridization state of the central atom.

sp2 hybridization corresponds to trigonal planar geometry. Let us recall that the presence of lone pairs causes a deviation of the molecular geometry from the expected geometry based on the number of electron pairs.

Hence, owing to one lone pair present, the observed molecular geometry is bent.

Answer:

The metal sphere was made of iron.

Explanation:

From the question,

Heat lost by the metal sphere = heat gained by the mercury.

Cm(t₁-t₃) = C'm'(t₃-t₂)................... Equation 1

Where C = specific heat capacity of the metal sphere, m = mass of the metal sphere, C' = specific heat capacity of the mercury, m' = mass of the mercury.

t₁ = initial temperature of the metal sphere, t₂ = initial temperature of the mercury, t₃ = Final temperature of the mixture.

Make C the subject of the equation

C = C'm'(t₃-t₂)/m(t₁-t₃)................. Equation 2

Given: m = 0.5 kg, m' = 4.08 kg, t₁ = 300 °C, t₂ = 20 °C, t₃ = 99 °C

Constant: C' = 140 J/kgK.

Substitute into equation 2

C = [140×4.08×(99-20)]/[0.5×(300-99)]

C = 45124.8/100.5

C = 449.0 J/kgK.

Hence from the specific heat capacity data sheet, the metal is suspected to  be  made of iron.

Answer: 78.125%

Explanation:

From the question, we are informed that a student obtained 2.00g of pure caffeine following recrystallization from a crude sample, which originally weighed 2.56g.

The percent recovery of pure caffeine from crude will be calculated as:

= Mass of pure caffeine / Mass of crude sample × 100

= 2.00 / 2.56 × 100

= 78.125%