Homework Help

Hello, as my username suggests... I am new to science and I am studying online so it is a bit harder to get help with my questions. I have answered the following sum but I have 3 possible answers (probably wrong) so i just want to confirm how to actually work this out properly to see if any of my answers are correct. Also how should I properly display the answer if asked to "give your answer in scientific notation and without any brackets" does this mean show my answer as a sum such as this: A x 10 to the power of B? (not sure how to write in small nexto the 10 to shower the power properly but I'm sure you understand what I mean above)

Hi my name is Sarah iv been stuck on this question for two days, if you could help my it would be amazing 😃 Chromium (II) sulfate is a reagent that has been used in certain applications to help reduce carbon-carbon double bonds to carbon-carbon single bonds. The reagent can be produced by the reaction of zinc, potassium dichromate and sulfuric acid and the other products are zinc sulfate, potassium sulfate and water. a) What is the maximum number of grams of chromium (II) sulfate that can be produced by a reaction mixture containing 3.2 moles of zinc, 1.7 moles of potassium dichromate and 5.0 moles of sulfuric acid? this is the equation i got hopefully i…

Hi My name is Sarah and I need help. Titanium tetrachloride (a gas), carbon monoxide and carbon dioxide can be created from the reaction of titanium (IV) oxide with carbon and chlorine. Iw much (in grams) of each of the excess reagents remain after the reaction takes place? This is the formula: I Think 2TiCl4+Co+Co2=3TiO2+4Cl2+c

Hi My name is Sarah I really need some help The potassium salt of benzoic acid, potassium benzoate, can be created by the reaction of potassium permanganate and toluene (C7H8(l)). By products of the reaction are manganese (IV) oxide, potassium hydroxide and water. If the yield of potassium benzoate cannot realistically be expected to be more than 68%, what is the minimum number of grams of toluene needed to achieve this yield while producing 10.0 g of potassium benzoate? Im just lost as of what to do I dont know if I got it but here is the formula. It just dosint look right to me KMn04+C7H8=Mno2+KOH+H2O

Here are 2 questions: 1. You have a probe pool at 1000 probes in a single pool. The pool concentration is 20nM. We use 5ul of this into our ligation reaction. What is the concentration of each probe in each reaction in fmol/probe? I calculated this out as 100fmol/reaction (20nM*5ul), then 0.1 fmol/probes (100fmol/1000probes). 2. You order some new probes to spike into the 20nM pool. You order as 10 probes in lyophiized (dried) form. You can resuspend dried tube how we want, then spike in some volume of it into the original 20nM probe pool. You want the final molarity to stay as above, 0.1fmol/probe. Calculate and make sure each probe (old and new) ar…

in a triangle ABC, AD is the bisector of angle BAC, meeting BC at D. if AC = 21 cm, BC =12 cm and the length of BD is 2 cm less than DC, then the length of side AB is:

I have a 1x1x1 feet box. I have a heating source in the box which produces "x" watts. How long will it take to increase the temperature of the box by 1 deg C? thankyou.

is sex linked and sex influenced the same thing? do traits that fall under either category also apply to the other one?

Our teacher asked us to use LCM method yo balance PCl5 + H2O. Please help me.

Hi all. I was just wondering how to write balanced dissociation equations (and how to determine the charge of things/the charge of compounds). For example, in class we were given a compound. It was CaCO3 (calcium carbonate). According to the answers, the products of the equilibrium reaction are Ca2+ + CO3-. My first question: How do we know what the products are going to be? (i.e. how do you know that the products aren't going to be Ca + C + O instead?). My second question: How do you know what charges the chemicals are going to have? I always assumed you could just use the periodic table, but our teacher said you can't for transition metals (why is that?). My…

It was reported that a mild earthquake occurred in brass with a result that the plate which is 0.8m square of 0.5m thick usually attached to the base of the antenna pole had its edges displaced by 0.016cm. If the plate is made of brass with a shear modulus of 0.36 x 10^11 N/m². Find the force exerted by the earthquake on the plate.

i need help with my air pressure homework.what happens to a bag of crisps when under water and why? i am only asking because i cant find the answer anywhere else! thx, silverwanderingdoe

Hi! I have been given a question and I have no clue about it, I researched in a lot of sites but nothing... If someone knows the answer to this question, PLEASE HELP! Why did chemists despise alchemists who tried to convert lead into gold?

Hello, I am a student attempting to do photography with Iron Salts and I have a problem. What exactly do these instructions mean? Mix 10 parts of ferrous oxalate (25% aqueous solution), 7 parts of concentrated ammonia solution, and 20 parts of a saturated solution of oxalic acid to produce a photosensitive iron complex. Prepare separately a 25% solution of potassium ferricyanide. Thanks.

Does this do a good job of naming the compound and explaining how I determined it? Step 1 Cation: Fe+3 Anion: O-2 Step 2 Iron has two oxidation numbers Fe+2 and Fe+3 The element iron (a transition metal) has an electron configuration of [Ar] 3d6 4s2 with atomic number 26. It has two electrons in its 4s orbital and 6 electrons in its 4d orbital. When iron loses the two 4s electrons, it attains a valency of +2. It can lose one of the paired electrons from the 3d subshell (which provides a more stable configuration), and it attains a valency of +3. Step 3 Fe2O3 = iron(III) oxide

Phosphorus pentachloride (PCI5) is an exception to the octet rule because it has more than 8 electrons around the valence shell. The chlorine atoms (PCI3) obey the octet rule because the atom has five electrons and need three to fulfill its octet, while the phosphorus atom does not. Phosphorus (PCI5) can form an expanded octet containing ten electrons in the 3d orbitals. is this correct?

Equation is not simplified. It should be Zn + 2HCl —> ZnCl2 + H2 How do do I explain what is wrong with this equation?

I have to show my work for this question and I’m not sure if this is the correct way to do it H2(g) + CI2(g) —> 2HCI(g) The balanced equation is H2 + CI2 —> 2HCI There are two hydrogen (H) atoms on the reactants side and two chlorine (CI) atoms on the reactants side. Two hydrogen (H) atoms and two chlorine (CI) atoms are produced. To balance them, we put a coefficient of 2 in front of the product hydrogen chloride (HCI).

Is this the correct explanation and Lewis structure for ch2O?

Energy increases as the electromagnetic wavelength decreases and the frequency increases. The energy of a wave is directly proportional to its frequency. A wave will transmit more energy per second if it has a higher frequency. Shorter wavelengths are more energetic than longer wavelengths. Is this correct?

Naming Oxyacids (oxyacids produce the H+ cation) The first step in writing a name for a formula is to decide which type of compound it represents. Determine the anion (the name of the acid is based on the anion attached to the hydrogen) The acid name comes from the root name of the oxyanion name or the central element of the oxyanion. Oxyanions are named according to the following rules: If the group ends in the suffix -ate (with more oxygen atoms bonded), it changes to -ic If the group ends in the suffix -ite(with less less oxygen atoms bonded), it changes to -ious Is this step process correct?

Hi Folks! I'm a newbie in this forum, I hope not to violate any rule with this post, in the case I apologize in advance I've got a list of doubts about Immuno exam, I am a Med student 1. what is the role of lectins and agglutinines in innate immunity? 2. entrance of immature T in thymus happens via blood? 3. once T mature in the thymus, thymus then athrophyzes. Where does maturation for the next T happen? I haven't got this clear... is it like for the oocytes? they just mature all once and that's it? 4. innate immunity: what are preformed effectors? [Janeway] are they AMP? 5. CD40:CD40L is it a stimulating interaction from T towards APC? has …

Is this done correctly? mass = 27.8 g CaCI2 Number of CaCI2 in the compound = (unknown) Number of CI- ions in the compound = (unknown) Number of moles = mass/molar mass To find the number of moles of CaCI2 first you find the molar mass of the compound. 1 mole Ca x 40.08 g Ca/1 mole Ca = 40.08 g 1 mole CI x 30.45 g CI/1 mole CI = 30.45 g 1 mole CI x 30.45 g CI/1 mole CI = 30.45 g molar mass = (40.08 g + 35.45 g + 35.45 g) = 110.98 g/mol CaCI2 27.8 g CaCI2 x 1 mol CaCI2/110.98 g CaCI2 = 0.250 mol CaCI2 Now from equation No of Chloride ions are : 6.02 x 10^23 x 2 CI- ion = 1.204 x 10^23 CI- ions

Can someone please help me with this? Im not sure what I’m doing wrong with the units. Convert the 100 yards to cm (there are 36 inches in a yard). Divide this by the length of the paperclip 1 yd = 36 in 1 in = 2.54 cm 100 yards = 9144 cm 100 yds * 36 in/1 yd * 2.54cm/1 in = 9144 cm 9144 / 3.2 = 2857.5 9144 cm/3.2 cm = 2,857.5 cm

Name: Iron (III) oxide C: Fe+3 A: O-2 Is this right?